Halides Held by Bifurcated Chalcogen-Hydrogen Bonds. Effect of μ(S,N-H)Cl Contacts on Dimerization of Cl(carbene)PdII Species

Article abstract of DOI:10.1021/acs.inorgchem.8b00190

The reaction of cis-[PdCl₂(CNCy)₂] (1) with thiazol-2-amines (2-10) leads to the C,N-chelated diaminocarbene-like complexes [PdCl{C(N(H)4,5-R₂-thiazol-2-yl)NHCy}(CNCy)] (11-14; 82-91%) in the case of 4,5-R₂-thiazol-2-amines (R, R = H, H (2), Me, Me (3), -(CH₂)₄- (4)) and benzothiazol-2-amine (5) or gives the diaminocarbene species cis-[PdCl₂{C(N(H)Cy)N(H)4-R-thiazol-2-yl}(CNCy)] (15-19; 73-93%) for the reaction with 4-aryl-substituted thiazol-2-amines (R = Ph (6), 4-MeC₆H₄ (7), 4-FC₆H₄ (8), 4-ClC₆H₄ (9), 3,4-F₂C₆H₃ (10)). Inspection of the single-crystal X-ray diffraction data for 15-17 and 19 suggests that the structures of all these species exhibit previously unrecognized bifurcated chalcogen-hydrogen bonding μ_(S,N-H)Cl and also Pd^II···Pd^II metallophilic interactions. These noncovalent interactions collectively connect two symmetrically located molecules of 15-17 and 19, resulting in their solid-state dimerization. The existence of the μ_(S,N-H)Cl system and its strength (6-9 kcal/mol) were additionally verified/estimated by a Hirshfeld surface analysis and DFT calculations combined with a topological analysis of the electron density distribution within the formalism of Bader's theory (AIM method) and NBO analysis. The observed noncovalent interactions are jointly responsible for the dimerization of 15-19 not only in the solid phase but also in CHCl₃ solutions, as predicted theoretically by DFT calculations and confirmed experimentally by FTIR, HRESI-MS, ¹H NMR, and diffusion coefficient NMR measurements. Available CCDC data were processed under the new moiety angle, and the observed μ_(S,E-H)Cl systems were classified accordingly to E (E = N, O, C) type atoms.

Full text of DOI:10.1021/acs.inorgchem.8b00190

Article
pubs.acs.org/IC
Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX
Halides Held by Bifurcated Chalcogen−Hydrogen Bonds. Effect of
μ(S,N−H)Cl Contacts on Dimerization of Cl(carbene)PdII Species
Alexander S. Mikherdov, Alexander S. Novikov, Mikhail A. Kinzhalov, Vadim P. Boyarskiy,*
Galina L. Starova, Alexander Yu. Ivanov, and Vadim Yu. Kukushkin*
Saint Petersburg State University, 7/9 Universitetskaya Nab., Saint Petersburg 199034, Russian Federation
S
* Supporting Information
ABSTRACT: The reaction of cis-[PdCl2(CNCy)2] (1) with thiazol-2-
amines (2−10) leads to the C,N-chelated diaminocarbene-like complexes
[PdCl{C(N(H)4,5-R2-thiazol-2-yl)NHCy}(CNCy)] (11−14; 82−91%) in
the case of 4,5-R2-thiazol-2-amines (R, R = H, H (2), Me, Me (3), −(CH2)4−
(4)) and benzothiazol-2-amine (5) or gives the diaminocarbene species cis-
[PdCl2{C(N(H)Cy)N(H)4-R-thiazol-2-yl}(CNCy)] (15−19; 73−93%) for
the reaction with 4-aryl-substituted thiazol-2-amines (R = Ph (6), 4-MeC6H4
(7), 4-FC6H4 (8), 4-ClC6H4 (9), 3,4-F2C6H3 (10)). Inspection of the single-
crystal X-ray diffraction data for 15−17 and 19 suggests that the structures of
all these species exhibit previously unrecognized bifurcated chalcogen−
hydrogen bonding μ(S,N−H)Cl and also PdII···PdII metallophilic interactions.
These noncovalent interactions collectively connect two symmetrically
located molecules of 15−17 and 19, resulting in their solid-state dimerization.
The existence of the μ(S,N−H)Cl system and its strength (6−9 kcal/mol) were
additionally verified/estimated by a Hirshfeld surface analysis and DFT
calculations combined with a topological analysis of the electron density distribution within the formalism of Bader’s theory
(AIM method) and NBO analysis. The observed noncovalent interactions are jointly responsible for the dimerization of 15−19
not only in the solid phase but also in CHCl3 solutions, as predicted theoretically by DFT calculations and confirmed
1
experimentally by FTIR, HRESI-MS, H NMR, and diffusion coefficient NMR measurements. Available CCDC data were
processed under the new moiety angle, and the observed μ(S,E−H)Cl systems were classified accordingly to E (E = N, O, C) type
atoms.
centers weak but noticeable S···Hal contacts are feasible only
for bifurcated CBs: viz. μ(Ch,Ch)Hal (Ch = S, Figure 1, A). It is
noteworthy that bifurcated types of noncovalent contacts play
an active role in some organocatalytic transformations (for a
recent review see ref 15; halogen bonding (XB) catalysts,16 CB
INTRODUCTION
■
The field of noncovalent interactions has grown explosively in
the past decade, warranting a recent special issue of Chemical
Reviews devoted exclusively to this topic.1 The hydrogen,2
halogen,3 chalcogen,4 pnictogen,5 and tetrel5a bonding, tetrel-
like σ-hole interactions involving Pb2+,6 stacking,7 cation− and
anion−π,8 and metallophilic interactions9 play key roles in
many chemical, physical, and biochemical processes due to
their ability to control the structures and properties of
associates and supramolecular systems from water dimeriza-
tion10 to protein folding.11
In particular, chalcogen bonding (CB) is based on the
interaction between a localized positive region, the so-called σ-
hole, on a chalcogen atom and an electron donor species
serving as a CB acceptor. The heavier chalcogens Te and Se12
are more prone to act as CB donors due to their higher
polarizability,4e,13 but most recent reports deal with CBs with
more abundant S centers.
Most common types of CBs with sulfur centers involve S···S,
S···O, and S···N interactions,4a,14 whereas S···Hal (Hal =
halide) contacts are substantially less common. While
intermolecular Te···Hal and Se···Hal CBs are rather strong
and these contacts are preserved even in solution,12d for S
Figure 1. Bifurcated bonding patterns (Ch = S, Se, Te; E = C, N, O).
Received: January 23, 2018
© XXXX American Chemical Society
A
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Scheme 1. Two Directions of the Reactions of cis-[PdCl2(CNR1)2] with Thiazol-2-amines
catalysts17) and in anion recognition and transfer (for a recent
review see ref 18; XB receptors,19 CB receptors20).
in a box in the scheme.24a The formed species were not isolated
because of their higher reactivity in comparison to that of
thiazol-2-amines, and they are subject to further reaction with
the other isocyanide complex, giving a mixture of two
regioisomeric binuclear diaminocarbenes. The equilibrium
(bottom left, Scheme 1) between these species mainly depends
on the energy difference between two different types of CB:
viz., S···Cl and S···N.
Being interested in an extension of these reactions to other
isocyanide species, we employed another isocyanide complex,
viz. cis-[PdCl2(CNCy)2] (1), and found that seemingly small
modification of the nature of the substituent R at CNR (Xyl
was replaced with Cy) led to a substantial change in the
reactivity and, what is even more important, to totally different
types of noncovalent interactions in the generated coupling
products (route B).
Whereas the classic bifurcated hydrogen bond (Figure 1, C)
is the subject of a large number of studies,18,21 noncovalent
bifurcated chalcogen−hydrogen bonding μ(Ch,E−H)Hal (Figure
1, B) has never been investigated as a separate phenomenon.
Although more than 600 examples of structures featuring the
μ(Ch,E−H)Hal moieties (B) can be found in the CCDC database,
the presence of both types of contacts, i.e. both Ch···Hal (CB)
and E−H···Hal (HB) within a single structure, was only briefly
mentioned in 20 reports (Table S1 in the Supporting
Information). None of these studies, except our previous
work on CB,22 discuss the nature of the Ch···Hal contacts or
recognize them as CBs. Thus, the μ(Ch,E−H)Hal functionality has
never been considered as a specific moiety with hetero-
bifurcated chalcogen−hydrogen μ(Ch,E−H)Hal (B) bonding.
In this work, we found that the complexes cis-[PdCl2{C(N-
(H)Cy)N(H)4-R-thiazol-2-yl}(CNCy)] (15−19; Scheme 1)
exhibit dimeric structures held together by the previously
overlooked bifurcated chalcogen−hydrogen bonding μ(S,N−H)Cl
(B) between two monomeric parts. The existence of these
interactions, observed by X-ray diffraction, was additionally
confirmed by DFT calculations combined with a topological
analysis of the electron density distribution within the
formalism of Bader’s theory (AIM method). The observed
noncovalent interactions are jointly responsible for the
dimerization of 15−19 not only in the solid phase but also in
CHCl3 (CDCl3) solutions, as predicted theoretically by DFT
calculations and confirmed experimentally by combined FTIR,
Reaction between cis-[PdCl2(CNCy)2] and Thiazol-2-
amines. We found that the reaction between 1 and 4,5-R2-
thiazol-2-amines (R1, R2 = H, H (2), Me, Me (3), −(CH2)4−
(4)) or benzothiazol-2-amine (5) gives mononuclear C,N-
chelated complexes 11−14 (82−91%; route C, Scheme 2). In
11−14, the newly formed ligands are of aminocarbene-like
Scheme 2. Studied Coupling
1
HRESI-MS, H NMR, and diffusion NMR methods. We have
additionally processed the available CCDC data using the new
moiety angle and verified and classified the μ(S,E−H)X moieties
on the basis of the nature of the E atom (E = N, O, C). These
results are discussed accordingly in the sections that follow.
RESULTS AND DISCUSSION
■
In the framework of our ongoing projects focused on metal-
involving reactions of isocyanides (for our reviews see ref 23)
on the one hand and on noncovalent interactions on the other
hand (for recent works see refs 22 and 24), we recently
reported on the reaction between cis-[PdCl2(CNXyl)2] (Xyl =
2,6-Me2C6H4) and various thiazol-2-amines (route A, Scheme
1) that leads to C,N-chelated aminocarbene complexes shown
B
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
type, as formally they are not carbenes because of their negative
charge.25 Concurrently, the treatment of 1 with any one of the
4-aryl-substituted thiazol-2-amines (R1 = Ph (6), 4-MeC6H4
(7), 4-FC6H4 (8), 4-ClC6H4 (9), 3,4-F2C6H3 (10), R2 = H;
route D, Scheme 2) leads to open-chain aminocarbene species
15−19 featuring neutral carbene ligands (73−93%). In all
cases, these reactions are palladium-mediated insofar as
uncomplexed CyNC does not react with 2−10.
Formation of two types of the products upon coupling with
unsubstituted and substituted thiazol-2-amines can be ration-
alized by the different reactivity patterns of these heterocyclic
systems.
is possibly due to involvement of the N−H protons in
hydrogen bonding;28 this was additionally confirmed by
theoretical calculations (see below). Addition of 2−10 to a
CNCy ligand of 1 is accompanied by disappearance of the
isocyanide quaternary carbon signal at δ 116.1 and appearance
of a new signal from the carbene NCN fragment at around δ
180 for 11−19. These signals are in the range specific for Pd−
Ccarbene (δC 160−224) in acyclic diaminocarbenes.29
The crystal data, data collection parameters, and structure
refinement data for 11, 15−17, and 19 are given in Table S1 in
the Supporting Information. The plots of the structures are
given in Figure 2 (complex 11) and Figure 3 (complexes 15−
Thiazol-2-amines (2−4) and benzothiazol-2-amine (5) react
with cis-[PdCl2(CNCy)2] (1) as ambident nucleophiles,
initially replacing the chloride ligand by the heterocyclic
nitrogen (route C, Scheme 2) and then attacking the isocyanide
ligand by the amino group. The second molecule of 2−5 acts as
a base, and it deprotonates the formed aminocarbene complex,
giving 11−14 and corresponding (2−5)·HCl. Introduction of
bulky substituents in the fourth position of the thiazole ring
(6−10) prevents the intramolecular nucleophilic addition of
the amino group and promotes the decoordination of 6−10
from palladium, and therefore these species react with CNCy in
1 only by the amino group (route D, Scheme 2). Yet more
evidence of the alternative mechanisms is the quite different
rates of these two reactions. While the reaction with 2 occurs in
C2H4Cl2 at room temperature for 2 h, the addition of 6
proceeds upon reflux in C2H4Cl2 for 24 h. The higher rate of
the former reaction is probably due to the intramolecular
character of the addition.26
The difference in the reactivity between the Xyl and Cy
palladium(II) complexes could be rationalized by the different
acidities of the intermediate cationic C,N-chelated amino-
carbene complexes (Schemes 1 and 2). In the case of the Xyl
derivative, the formed aminocarbene complex bearing the more
acidic N−H protons is subject to easy two-step deprotonation
by a thiazol-2-amine followed by coupling with the other
XylCN complex, giving the binuclear species (Scheme 1). The
less acidic Cy-substituted diaminocarbene species is subject to
only one-step deprotonation, giving complexes 11−14, which
are not involved in further reactions (Scheme 2).
Figure 2. View of 11 with the atomic numbering scheme. Thermal
ellipsoids are drawn at the 50% probability level.
17 and 19). The geometry of these complexes is in agreement
with the structures proposed from the solution NMR
experiments (Supporting Information). In all cases, the Pd
centers adopt slightly distorted square-planar geometries with
the isocyanide ligand in the cis-position to the diaminocarbene
fragment. The bond lengths of the coordinated CN groups are
in the range 1.132−1.157 Å, which is the typical interval for CN
triple-bond lengths in related isocyanide palladium complexes:
Characterization of 11−19. The pure complexes were
obtained as colorless or yellow solids, and they were
characterized by microanalyses (C, H, N), high-resolution
ESI-MS, FTIR, TG/DTA, and 1D (1H, 13C{1H}, 19F{1H}) and
2D (1H,1H-COSY, 1H,1H-NOESY, 1H,13C-HSQC, and 1H,13C-
HMBC) NMR spectroscopy and also by X-ray diffraction for
five species (11, 15−17, and 19) (Supporting Information).
The HRMS-ESI+ spectra of all new complexes display
fragmentation patterns corresponding to [M − Cl]+ and/or
[M + H]+ with the characteristic isotopic distribution. In
addition, the HRMS-ESI+ spectra of 15−19 display fragments
from [2M − Cl]+.
e.g., cis-[PdCl2(CNR)2] (R = Cy, 1.128−1.142 Å;30 R = Bu,
t
1.108−1.149 Å;31 R = Xyl, 1.145−1.156 Å).32 The Pd−Ccarbene
distances (11, 2.004(3) Å; 15, 1.988(3) Å; 16, 1.978(2) Å; 17,
1.999(6) Å; 19, 1.992(6) Å) are comparable to those reported
for related palladium aminocarbene complexes: e.g., cis-
[PdCl2(CNCy){C(ProOtBu)NHCy}] (1.983(2) Å),27e cis-
[PdCl2 {C(NHNHS(O)2 Ph)N(H)Cy}(CNCy)]
(1.9781(16) Å),27b and cis-[PdCl2{C(Ind)N(H)Cy}-
(CNCy)] (1.976(3) Å).27c The C−N bond lengths in the
NCN fragment are nearly equal (11, 1.332(3) and 1.334(4) Å;
15, 1.362(5) and 1.308(5) Å; 16, 1.349(4) and 1.306(4) Å; 17,
1.354(10) and 1.288(9) Å; 19, 1.353(6) and 1.290(5) Å) and
are intermediate between the typical double (1.260(9) Å)33 and
single (1.452(8) Å)33 bonds, thus reflecting their diamino-
carbene nature.27a,b,e,h,34
The 1H NMR spectra exhibit resonances from the two
characteristic C−H protons of the cyclohexyl groups as two
overlapped signals at δ ca. 4.0−4.2 for 11−14 or two separate
signals in the range from δ 4.0 to 4.9 for 15−19. The positions
of the NH protons for both types of complexes are also
different. In the case of 11−14, only one signal is located in the
range δ 5.2−5.7, whereas for 15−19 two NH protons were
observed as a singlet at δ ca. 11.4−11.6 and as a doublet at δ ca.
11.7−11.8. The strong downfield shift of these signals is
unusual for palladium aminocarbene complexes,27 and this shift
C
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Figure 3. Views of dimers of 15 (a), 16 (b), 17 (c), and 19 (d). Dotted lines indicate the bifurcated μ(S,N−H)Cl and Pd···Pd contacts and
intramolecular N−H···N HBs. Thermal ellipsoids are shown with 50% probability. The cyclohexyl substituents are omitted for simplicity.
Table 1. Distances (Å) and Angles (deg) for Two Types of Noncovalent Contacts in the Structures of 15−17 and 19
intermolecular bifurcated μ(S,N−H)Cl
intramolecular HB
compound
d(S···Cl)
∠(C−S···Cl)
d(H···Cl)
d(N···Cl)
∠(N−H···Cl)
d(H···N)
d(N···N)
∠(N−H···N)
15
16
17
19
3.4509(11)
3.4985(9)
3.495(2)
166.37(11)°
172.35(13)°
171.7(3)°
2.27(5)
2.30(5)
2.33(5)
2.37(5)
3.108(3)
3.119(3)
3.133(6)
3.149(3)
164(1)°
157(1)°
153(1)°
149(1)°
1.98(5)
1.91(5)
1.98(5)
1.96(5)
2.692(3)
2.649(3)
2.679(7)
2.662(5)
139(1)°
141(1)°
136(1)°
137(1)°
3.5428(12)
167.44(13)°
Comparison
Bondi’s vdW36
Rowland’s vdW37
3.55
3.57
180
180
2.95
2.86
3.30
3.40
180
180
2.75
2.74
3.10
3.28
180
180
All other bond lengths are usual, and their values agree with
those reported for related palladium(II) carbene and isocyanide
complexes.27a,b,e,h,34,35
(Pd + Pd 3.26 Å36), but less than the sum of Allinger vdW radii
(Pd + Pd 4.66 Å39), and the latter suggests the possibility of
existence of metallophilic Pd···Pd interactions. The availability
of these contacts was confirmed theoretically by a DFT study
(see below), which also gave an estimate of their energy.
In the structures of 15−17 and 19, one of the two amino
groups from the diaminocarbene fragment is involved in the
intramolecular HB N2−H2···N3, thus forming a six-membered
cycle. The distances between the N3 and H2 atoms and
between the N3 and N1 atoms (Table 1) are substantially less
than the sum of their Rowland37 or Bondi36 vdW radii. The
corresponding angles are in the range 136−141°, and these
contacts could be interpreted as HB in according with the
IUPAC criterion.40
Moreover, in the structures of 15 and 16 geometric
parameters for two weak C−H···Cl contacts, viz. between
CyNC and chloride ligands, disagree with the HB IUPAC
criterion40 for HB, as both H18−Cl1 (3.00(5) Å for 15,
2.81(5) Å for 16) and C18−Cl1 (3.598(4) Å for 15, 3.547(3)
Å for 16) distances are greater than the sum of their Rowland37
and Bondi vdW36 radii of these atoms. However, we recognized
these contacts as HBs by DFT calculations (see below).
Theoretical Approach. Inspection of the crystallographic
data indicates the presence of several types of noncovalent
interactions in the dimers of 15−17 and 19: viz., the bifurcated
CB−HB μ(S,N−H)Cl, intermolecular metallophilic interactions
Pd···Pd, and intramolecular HB N−H···N. To confirm or
disprove the hypothesis of the existence of these weak
Noncovalent Interactions in the Crystal Structures of
15−17 and 19. Experimental Approach. The XRD data for
15−17 and 19 indicate several types of noncovalent
interactions: namely, intermolecular interactions between two
symmetrically located neighboring molecules, i.e. bifurcated
μ(S,N−H)Cl bonding, metallophilic PdII···PdII interactions, and
intramolecular N−H···N hydrogen bonding (HB) (Figure 3).
The geometric parameters for these noncovalent contacts are
given in Table 1.
The intermolecular interactions collectively connect two
symmetrically located molecules in 15−17 and 19, providing
their solid-state dimerization. In all cases, the S1 and H1 atoms
in each molecule are linked with PdII-bound chloride (Cl2) in
the neighboring molecule. The distances (Table 1) between the
Cl2 and H1 and between the Cl2 and N1 atoms are less than
the sum of their Rowland37 or even Bondi36 vdW radii, and the
corresponding angles N1−H1−Cl2 are within the 110−180°
range that is specific for a classic HB. The S1−Cl2 distances are
also less than the sum of their Rowland37 or Bondi36 vdW radii
of these atoms, and the angles C3−S1−C2 are in the range
150−180°; thus, this contact was explicitly recognized as
CB4d,e,38 between the sulfur and the chlorine centers.
The distances between the palladium atoms in the dimers
(15, 3.9608(5) Å; 16, 4.1533(6) Å; 17, 4.1728(13) Å; 19:
4.1996(7) Å) are greater than the sum of the Bondi vdW radii
D
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
interactions in the solid state, to quantify their energies, and to
determine the influence of crystal-packing effects on the
geometric features of the dimers, we carried out a Hirshfeld
surface analysis of the crystal structure and DFT calculations
and performed topological analysis of the electron density
distribution within the formalism of Bader’s theory (AIM
method)41 for the dimeric structure of 15 taken as a model.
This approach has already been successfully used by us in
studies of noncovalent interactions and properties of
coordination bonds in various transition-metal complex-
es.22,24a,d,f−j,42
The molecular Hirshfeld surface represents an area where
molecules come into contact, and its analysis gives the
possibility of an additional insight into the nature of
intermolecular interactions in the crystal state. For visualization,
we have used a mapping of the normalized contact distance
(dnorm); a negative value enables identification of molecular
regions of substantial importance for the detection of short
contacts. Figure 4 depicts the Hirshfeld surface of one complex
(RDG) analysis43 was carried out, and RDG isosurfaces were
plotted (Figures 5 and 6). The Poincare−Hopf relationship is
satisfied; thus, all critical points have been found.
In order to exclude the crystal-packing effects from
consideration, we optimized the structure of the isolated
supramolecular dimeric associate of 15 in the gas phase using
the experimental X-ray geometry as a starting point. If the
crystal-packing effects are significant, the structure should
change appreciably on going from the solid state to the gas
phase; otherwise the geometry is preserved in the isolated form.
The geometry optimization leads to a very slight asym-
metrical distortion of the dimer of 15 and to significant
shortening of the H···Cl contacts (by 0.10−0.12 and 0.31−0.33
Å); the S···Cl contacts contracted to a much lesser degree (by
0.05 Å), whereas the Pd···Pd separation remained unchanged.
The AIM analysis demonstrates the presence of bond critical
points (BCPs) (3,−1) for all noncovalent interactions discussed
above and also for one additional pair of intermolecular
hydrogen bonds H···Cl, whose parameters disagree with the
IUPAC criterion40 (C···Cl and H···Cl distances are greater than
the sum of the Rowland37 or Bondi36 radii of these atoms)
(Figure 6).
The low magnitude of the electron density (0.005−0.034
hartree), positive values of the Laplacian (0.011−0.108
hartree), and close to zero energy density (−0.002−0.002
hartree) in these BCPs are typical for noncovalent interactions.
We have defined energies for these contacts according to the
procedures proposed by Espinosa et al.44 and Vener et al.45
(Table 2), and one can state that metallophilic interactions
Pd···Pd and CB S···Cl in the dimer of 15 are very weak,
whereas HBs N−H···N and H···Cl may be classified as
moderate and weak strength contacts following the classi-
fication of Jeffrey (“strong” H bonds, 40−15 kcal/mol;
“moderate” H-bonds, 15−4 kcal/mol; “weak” H-bonds, <4
kcal/mol).21c The balance between the Lagrangian kinetic
energy G(r) and potential energy density V(r) at the bond
critical points (3,−1) reveals the nature of these interactions: if
the ratio −G(r)/V(r) > 1 is satisfied, then the nature of
appropriate interaction is purely noncovalent; if −G(r)/V(r) <
1, some covalent component is present.47 On the basis of this
criterion one can state that in 15 the covalent contribution in
the metallophilic interaction Pd···Pd, CB S···Cl, and HB H···Cl
is absent, but it is available (although almost negligible) in HBs
H···Clbif and N−H···N. The negligible nonzero values of the
Wiberg bond indices for Pd···Pd, S···Cl, H···Clbif, H···Cl, and
N−H···N contacts in the optimized structures of the dimer of
15 (Table 2) computed by using the natural bond orbital
(NBO) partitioning scheme48 additionally confirm the electro-
static nature of these noncovalent interactions.
Since the chlorine and sulfur atoms have electron pairs and
σ-holes, they both can act as electron donors and/or
acceptors.49 To define the direction of charge transfer (CT)
in this system, we applied NBO analysis. In the case of
μ(S,N−H)Cl, the NBO analysis revealed the intermolecular
charge transfers from the Cl ligands to the {S−C} and {N−
H} moieties in the optimized gas-phase equilibrium structure
for the dimer of 15. A second-order perturbation theory
analysis indicates that these intermolecular charge transfers are
mainly associated with the transitions LP(Cl) → σ*(S−C) and
LP(Cl) → σ*(N−H); the total E(2) values are 2.6 and 36.2
kcal/mol, respectively. The calculated NBO atomic charges on
the appropriate Cl, S, and H atoms are −0.47, 0.49, and 0.47,
correspondingly.
Figure 4. Hirshfeld surface of one PdII complex molecule in the crystal
structure of 15 with a colored scale, which corresponds to values
ranging from −0.5 Å (red) to 1.8 Å (blue).
molecule in the crystal structure of 15. In this Hirshfeld surface,
the regions of bifurcated CB−HB, μ(S,N−H)Cl, are visualized by
small (CB) and large (HB) red circled areas. The following
intermolecular contacts give the largest contributions to the
Hirshfeld surface: H−H, 52.1%; H−Cl, 20.2%; H−C, 12.8%;
H−S, 4.0%; H−N, 2.3%; C−C, 2.0%; C−N, 1.7%; S−Cl, 1.7%.
Individual contributions of other intermolecular contacts (viz.,
Pd−Pd, Pd−N, Pd−H, Pd−C, N−Cl, C−Cl, and S−S) are less
than 1% and their additive contribution is 3.1%. Thus, the
Hirshfeld surface analysis of 15 confirms that the solid dimeric
associates are formed by various types of intermolecular
contacts and, in particular, by the bifurcated μ(S,N−H)Cl linkage.
However, this analysis does not answer the question of the
energies of these contacts and, therefore, the DFT calculations
needed to be further performed.
To study the nature and strengths of these noncovalent
interactions, we carried out DFT calculations and topological
analysis of the electron density distribution within the
formalism of Bader’s theory (AIM method).41 The results are
summarized in Table 2; the contour line diagrams of the
Laplacian distribution ∇2ρ(r), bond paths and selected zero-
flux surfaces for 15 are shown in Figures 5 and 6. To visualize
studied noncovalent interactions, reduced density gradient
E
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Table 2. Values of the Density of All Electrons (ρ(r)), Laplacian of Electron Density (∇2ρ(r)), Energy Density (Hb), Potential
Energy Density (V(r)), and Lagrangian Kinetic Energy (G(r), hartree) at the Bond Critical Points (3,−1), Corresponding to
Noncovalent Interactions in 15 (M06/6-31G* Levels of Theory, MWB28 Pseudopotentials on the Pd Atoms), Appropriate
Bond Lengths (d, Å), and Wiberg Bond Indices (WI), as well as Energies for These Contacts (Eint, kcal/mol), Defined by Three
a
Approaches: Quasi-Solid-State (Experimental X-ray Geometry ), Optimized Geometry in the Gas Phase, and Optimized
Geometry in CHCl3 Solution
b
c
phase
ρ(r)
∇2ρ(r)
Hb
V(r)
G(r)
Eint
Eint
d(WI)
3.45
S···Cl
solid state
0.008
0.008
0.009
0.009
0.008
0.008
0.027
0.027
0.030
0.031
0.028
0.027
0.001
0.001
0.002
0.002
0.001
0.001
−0.004
−0.004
−0.005
−0.005
−0.004
−0.004
0.005
0.005
0.006
0.006
0.005
0.005
1.3
1.3
1.6
1.6
1.3
1.3
1.4
1.4
1.6
1.6
1.4
1.4
3.45
gas phase
3.40 (0.01)
3.40 (0.01)
3.45 (0.01)
3.46 (0.01)
CHCl3 solution
H···Clbif
solid state
0.022
0.022
0.029
0.028
0.026
0.026
0.075
0.075
0.078
0.077
0.072
0.072
0.000
0.000
−0.018
−0.018
−0.023
−0.022
−0.020
−0.020
0.018
0.018
0.021
0.021
0.019
0.019
5.7
5.7
7.2
6.9
6.3
6.3
4.9
4.9
5.7
5.7
5.1
5.1
2.27
2.27
gas phase
−0.002
−0.001
−0.001
−0.001
2.15 (0.09)
2.17 (0.08)
2.20 (0.07)
2.20 (0.07)
CHCl3 solution
H···Cl
solid state
0.006
0.006
0.010
0.011
0.008
0.008
0.021
0.021
0.035
0.037
0.026
0.026
0.001
0.001
0.002
0.002
0.001
0.001
−0.003
−0.003
−0.006
−0.006
−0.004
−0.004
0.004
0.004
0.007
0.008
0.005
0.005
0.9
0.9
1.9
1.9
1.3
1.3
1.1
1.1
1.9
2.2
1.4
1.4
3.00
3.00
gas phase
2.69 (0.01)
2.67 (0.01)
2.84 (0.01)
2.84 (0.01)
CHCl3 solution
N−H···N
solid state
0.028
0.028
0.034
0.034
0.032
0.033
0.107
0.107
0.107
0.108
0.103
0.106
0.001
0.001
−0.025
−0.025
−0.028
−0.028
−0.027
−0.027
0.026
0.026
0.027
0.028
0.026
0.027
7.8
7.8
8.8
8.8
8.5
8.5
7.0
7.0
7.3
7.5
7.0
7.3
1.98
1.98
gas phase
−0.001
−0.001
0.000
1.91 (0.05)
1.90 (0.05)
1.93 (0.05)
1.91 (0.05)
CHCl3 solution
−0.001
Pd···Pd
solid state
0.006
0.006
0.005
0.012
0.014
0.011
0.000
0.000
0.000
−0.003
−0.003
−0.002
0.003
0.003
0.002
0.9
0.9
0.6
0.8
0.8
0.5
3.96
gas phase
3.96 (0.03)
4.08 (0.03)
CHCl3 solution
a
We also carried out additional DFT calculations and performed topological analysis of the electron density distribution within the formalism of
Bader’s theory (AIM method) for the dimeric structure of 15 (experimental X-ray geometry) using the popular dispersion-corrected hybrid
functional ωB97XD.46 The results are presented in Table S5 in the Supporting Information; the obtained values of the density of all electrons,
Laplacian of electron density, energy density, potential energy density, and Lagrangian kinetic energy at the bond critical points (3, −1),
corresponding to noncovalent interactions S···Cl, H···Clbif, H···Cl, N−H···N, and Pd···Pd, are almost the same as those found when the M06
b
functional is used. Thus, the estimated energies for the studied noncovalent interactions are almost independent of the DFT functional used. Eint
=
c
−V(r)/2.44 Eint = 0.429G(r).45
The calculated vertical total energy (Ev,gas) for the dimer
cleavage in gas phase is 57.4 kcal/mol (Figure S3 in the
Supporting Information), which is comparable with, for
instance, the energy of typical covalent C−N bonding in
nitro compounds (50.5−72.5 kcal/mol).50
Retrieved and Processed CCDC Data for Bifurcated
Chalcogen−Hydrogen μ(S,E−H)Cl Bonding (E = C, N, O).
Our processing of available CCDC data explicitly indicates that
the μ(S,E−H)Cl (E = C, N, O) pattern is the most abundant
among the chalcogen−hydrogen bonding μ(Ch,E−H)Hal (Ch = S,
Se, Te). However, even the μ(S,E−H)Cl functionality has not
been classified as a specific moiety and the presence of both
short contacts, namely separately S···Cl and separately E−H···
Cl in one structure, were mentioned only in 11 reports (Table
3).22,51 As indicated in the Introduction, the nature of CB in
these species was recognized only by us in the solid state
structure of trans-[PtCl2(NCSEt)2].22 All examples retrieved
from the CCDC data and obtained from the literature could be
systematized according to two parameters: viz., HB donor (C−
H, N−H, O−H; Figure 7A) and source of Cl such as chloride
anion, metal chloride complexes, and organic R−Cl species
(Figure 7B). The dominant part of the published examples
relates to the structures featuring both S···Cl and N−H···Cl
contacts with metal-bound chlorides or chloride anion; these
μ(S,N−H)(Cl−[M]) and μ(S,N−H)(Cl−) groups were identified by
us in 6 species. Only a few reports deal with μ(S,C−H)Cl
bifurcates (5 structures), and only 1 example of the bifurcate
featuring μ(S,O−H)Cl− moiety has been reported.
Dimerization of 15−19 in Solution: Experimental and
Theoretical Considerations. The dimeric structure of 15−17
and 19 in the solid state allowed the assumption that the
dimerization also occurs in solution. The relevant dimeric
F
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Cl contact remained almost unchanged. The results of AIM
analysis of the equilibrium geometry of the dimer in a CHCl3
solution are given in Table 2. To estimate the stability of the
dimer in solution, we have employed two different approaches.
First, we calculated the vertical total energy for the dimer
cleavage on two monomeric parts with frozen coordinates in
CHCl3 solution (Ev,solv = ∑Em,solv − Ed,solv; Figure S3) and
found that it is also very high (56.5 kcal/mol). The
contribution of the intermolecular bifurcated CB−HB
μ(S,N−H)Cl to the dimer stabilization in a CHCl3 solution is
23−27%. Second, we performed full geometry optimization of
the monomer of 15 and estimated the energy profit of its
dimerization in CHCl3 solution in terms of Gibbs free energy
(ΔGsolv = Gd,solv − 2Gm,solv; Figure S4), and this process is
thermodynamically favorable by −9.3 kcal/mol. It is notable
that the quantitative data might be overestimated because of
the known uncertainty in the description of solvent effects53
and entropy terms.54 Nevertheless, the obtained theoretical
results indicate that the dimerization is highly probable and
these data encouraged the conductance of further experimental
studies to prove the dimerization in solution.
Experimental Verification. Comparison of the FTIR spectra
in the solid state (KBr) with those in a CHCl3 solution does
not indicate any difference in positions for ν(N−H) bands (ca.
3180 cm−1). The HRESI+ mass spectra of 15−19 exhibit the
[2M − Cl]+ peaks, which were not previously reported for
other relevant diaminocarbene complexes. In addition, strong
1
downfield shifts of the NH protons in the H NMR spectra (δ
11.4−11.8 for 15−19 in CDCl3) are unusual for conventional
complexes with acyclic diaminocarbene ligands (δ ranges from
δ ca. 5.5 for electron-donor substituents to δ ca. 10.5 for
strongly electron withdrawing substituents) and more resemble
diaminocarbene species where the N−H protons are involved
in intra- or intermolecular HB (δ 9.0−15.527g,h,52,55). These
data collaterally confirm the presence of the dimeric associates
in solution.
Figure 5. Contour line diagrams of the Laplacian distribution ∇2ρ(r),
bond paths and selected zero-flux surfaces (left) and RDG isosurfaces
(right) referring to the noncovalent interactions in the solid-state
structure of 15 (intermolecular metallophilic interactions Pd···Pd, top;
intermolecular heterobifurcated chalcogen/hydrogen bonding, middle;
intramolecular hydrogen bonding N−H···N, bottom). Bond critical
points (3,−1) are shown in blue, nuclear critical points (3,−3) in in
pale brown, and ring critical points (3,+1) in orange. Lengths are given
in Å and RDG isosurface values in hartrees.
On the other hand, complex 15 (which was chosen again as a
model, now because of its good solubility in CDCl3) exhibits
1
negligible concentration dependence of the H NMR signal of
the NH proton involved in intermolecular HB: viz., from δ
11.53 to 11.44 in the concentration range from 100 to 1.5 mM
(Figure S5). The presence of such concentration dependence
reveals fast exchange between the monomeric and dimeric
forms of 15. However, such weak dependence between the
chemical shift and concentration probably suggests that the
equilibrium between these two forms is shifted to one species
in the studied concentration range.56
In order to study in more detail the dimerization of 15 in
solution, we conducted NMR measurements of diffusion
coefficients (D). The D values exhibit fair sensitivity to the
effective size of supramolecular associates in solution.57 Under
the conditions of fast exchange between the monomeric and
dimeric forms of 15, the observed diffusion coefficient (Dobs) is
an average of the species excising in a solution weighted with
their relative amount. A series of D measurements were
performed for 15 in CDCl3, at concentrations ranging from 159
to 26 mM. To eliminate the effect of variable viscosity at
different concentrations on the Dobs value, tetramethylsilane
(TMS) was used as an internal standard, which not subject to
association, and the values of DTMS/Dobs were applied for
further calculations. The first parameter we used to estimate the
degree of dimerization of 15 in solution is an aggregation
number N, which is defined as (D0/Dobs)3, where D0
structure pattern has previously been observed by Espinet et
al.52 for the (diaminocarbene)AuI chloride (Figure 8), where
the dimer is stabilized by the two intermolecular N−H···Cl
HBs and by one aurophilic interaction. The presence of these
contacts in the solid state was proved by X-ray diffraction,
1
whereas for solution it was confirmed by H NMR spectros-
copy (strong downfield shifts of the NH protons: viz., δ 12.4)
and luminescence spectroscopy (characteristic emission shift
specific for the aurophilic interactions). To confirm or disprove
the presence of the dimeric form of 15−19 in solution, we have
employed combined experimental and theoretical approaches.
Theoretical Results. The high value of Ev,gas for the dimer of
15, taken as a model, implies the high stability of such an
associate in the gas phase, and to study theoretically the
influence of solvation effects on geometrical features and
stability of the dimer of 15, we carried out its full geometry
optimization in CHCl3 solution. In this case, the Pd···Pd
contact was elongated (by 0.12 Å), H···Clbif and H···Cl contacts
were shortened (by 0.07 and 0.16 Å, respectively), and the S···
G
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Figure 6. (top) View of the dimeric structure of 15. Dotted red lines indicate the additional pair of intermolecular hydrogen bonds H···Cl verified by
the AIM analysis. (bottom left) Contour line diagram of the Laplacian distribution ∇2ρ(r), bond paths and selected zero-flux surfaces and (bottom
right) RDG isosurface referring to these noncovalent interactions in the solid-state structure of 15. Bond critical points (3,−1) are shown in blue and
nuclear critical points (3,−3) in pale brown. Lengths are given in Å and RDG isosurface values in hartrees.
Table 3. Verification of the Chalcogen−Hydrogen Bonding μ(S,E−H)Cl via Our CCDC Data Processing and Inspection of
Corresponding Geometrical Parameters
compound/structure in CCDC
d(S···Cl)
∠(X−S···Cl)
d(E···Cl)
d(H···Cl)
∠(E−H···Cl)
source of Cl
μ(S,C−H)Cl
[PtCl2(NCSEt)2]22/OJIMIF
3.2987(7)
3.3812(6)
3.3743(9)
3.5039(10)
3.5136(11)
168.12(9)
177.83(6)
167.93(7)
158.46(9)
170.58(9)
3.507(4)
3.4487(19)
3.450(2)
3.517(3)
3.503(3)
2.9887(6)
2.7276(4)
2.8845(6)
2.9029(7)
2.8240(8)
114.7(2)
Pt−Cl moiety
Zn−Cl moiety
Co−Cl moiety
In−Cl moiety
Zn−Cl moiety
[ZnCl2{NCNC(MeS)2}2]51a/MUZYIR
[CoCl2{NCNC(MeS)2}2]51b/PAFZOO
[InCl3(4-bithiazole)(DMSO)]51c/PAKYEH
[Zn(μ3-4-pyridylthio)(acetate)Cl]n51d/LALYEE
130.77(10)
124.93(12)
116.68(15)
127.84(16)
Comparison
Bondi’s vdW36
Rowland’s vdW37
3.55
3.57
180
180
3.53
3.45
2.95
2.86
180
180
μ(S,N−H)Cl
[2-aminobenzo[d]thiazol-3-ium][SnCl6]51e/WAZJOY
3.385(3)
3.412(4)
177.2(2)
170.9(5)
3.283(7)
2.486(2)
2.663(3)
154.4(4)
147.5(6)
Sn−Cl moiety
Pb−Cl moiety
[5-bromo-2-aminobenzo[d]thiazol-3-ium][PbCl4Ph2]51f
YEKQIP
/
3.503(10)
[5-amino-2-sulfonamidethiadiaz-4-ium]Cl51g/OXUVOT
[6{tHPMT2}Cl3I4(I3)3]51h/FEBZUJ
[2{tHPMT2}Cl(I3)3]51h/FECBAS
[2{TU}(Cl)(I)(I3)]51i/GITPUW
3.4599(17)
3.482(2)
168.31(14)
166.3(1)
3.148(4)
3.141(6)
3.200(6)
3.155(5)
2.3420(12)
2.2873(14)
2.3695(4)
2.31261(9)
156.3(3)
163.5(4)
162.3(4)
166.5(4)
uncomplexed Cl−
uncomplexed Cl−
uncomplexed Cl−
uncomplexed Cl−
3.314(2)
163.21(12)
162.38(9)
3.4229(13)
Comparison
Bondi’s vdW36
Rowland’s vdW37
3.55
3.57
180
180
3.3
3.4
2.95
2.86
180
180
μ(S,O−H)Cl
169.2(3)
Comparison
(H-thiamine)2[PtCl6]Cl2•2H2O51j/ WECBUB
3.487(3)
3.137(8)
2.190(3)
150.1(4)
Uncomplexed Cl−
Bondi’s vdW36
Rowland’s vdW37
3.55
3.57
180
180
3.27
3.34
2.95
2.86
180
180
corresponds to the formal absence of association upon infinite
dilution, obtained by extrapolating the DTMS/Dobs value to zero
concentration of 15 (Figure 9) and is equivalent to the
diffusion coefficient of the monomer.57a,b,58 At the highest
H
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
and benzothiazol-2-amine 5) or open-chain aminocarbene
species 15−19 (for the 4-aryl-substituted thiazol-2-amines 6−
10) (Scheme 1). Inspection of single-crystal X-ray diffraction
data (Figure 3) indicates that 15−17 and 19 exhibit dimeric
structures stabilized by previously unreported bifurcated
chalcogen−hydrogen bonding μ(S,N−H)Cl accompanied by
Pd···Pd and hydrogen bond interactions between the two
monomeric parts. The presence of a μ(S,N−H)Cl moiety in the
XRD structure of 15 was confirmed by Hirshfeld surface
analysis (Figure 4) and DFT calculations (M06/6-31G* level
of theory, MWB28 pseudopotentials on the Pd atoms)
combined with a topological analysis of electron density
distribution within the formalism of Bader’s theory (AIM
method). The natural bond orbital analysis revealed that both
LP(Cl)→σ*(S−C) and LP(Cl)→σ*(N−H) charge transfers
are important in the bifurcated μ(S,N−H)Cl contacts.
Figure 7. Bifurcated chalcogen−hydrogen bonding μ(S,E−H)Cl.
In a CHCl3 solution, this μ(S,N−H)Cl linkage, again along with
metallophilic interactions and hydrogen bonding, is responsible
for the dimerization of 15−19, as predicted theoretically by
DFT calculations and confirmed experimentally upon analysis
1
of the obtained FTIR, HRESI-MS, H NMR, and diffusion
coefficient NMR data (for complex 15 taken as a model).
Our processing of available CCDC data along with a
Chemical Abstracts search indicates that μ(S,N−H)Cl, and more
generally the noncovalent bifurcated heteroatom−hydrogen
bonding μ(Ch,E−H)X (Ch = chalcogen; X = halide), have never
been studied as separate phenomena. Our work is thus first to
identify this bonding and to recognize its role in noncovalent
associations.
Figure 8. Dimeric diaminocarbene complex of gold(I) stabilized by
intermolecular N−H···Cl HBs and aurophilic interaction.52
EXPERIMENTAL SECTION
■
Materials and Instrumentation. Solvents, PdCl2, thiazol-2-
amines 2−4 and benzothiazol-2-amine 5, ketones S1−S5 (see the
Supporting Information), and CNCy were obtained from commercial
sources and used as received. The complex cis-[PdCl2(CNCy)2] (1)
and thiazol-2-amines 6−10 were synthesized by the known
procedures.29c,59 The C, H, and N elemental analyses were carried
out on a Euro EA 3028 HT CHNSO analyzer. The mass spectra were
obtained on a Bruker micrOTOF spectrometer equipped with
electrospray ionization (ESI) source; CH2Cl2 was used as a solvent.
The instrument was operated at positive ion mode using an m/z range
of 50−3000. The capillary voltage of the ion source was set at −4500
V (ESI+) and the capillary exit at (70−150) V. The nebulizer gas
pressure was 0.4 bar and drying gas flow 4.0 L/min. The most intense
peak in the isotopic pattern is reported. Infrared spectra were recorded
on a Shimadzu IRAffinity-1S FT-IR spectrometer (4000−400 cm−1) in
KBr pellets for solid samples and in IR cells (NaCl; l = 0.13 mm) for
CHCl3 solutions. TG/DTA measurements were performed with a
NETZSCH TG 209 F1 Libra thermoanalyzer. The initial weights of
the samples were in the 0.6−1.6 mg range. The experiments were run
in an open alumina crucible under a stream of argon at a heating rate
of 10 K min−1. The final temperature of the experiments was 450 °C.
1D (1H, 400 MHz; 13C{1H}, 101 MHz; 19F{1H}, 376 MHz; diffusion
coefficient measurements) NMR spectra were acquired on a Bruker
Figure 9. Dependence of DTMS/Dobs vs concentration of 15 (CDCl3,
298 K).
acceptable concentration of 159 mM the aggregation number
(N) of 15 is 1.33, revealing that it probably exists mostly in the
monomeric form at 298 K (Table S6).
Additionally, knowing N, C0, and the ratio of hydrodynamic
volumes of monomer and dimerwhich could be taken from
computation (for details see the Supporting Information)we
estimated the dimerization constant of 15 in CDCl3. The value
obtained at 298 K is 1.5 0.5 M−1, and it indicates that ca. 25%
of 15 exists as a dimer at the maximum solution concentration.
Thus, our combined theoretical and experimental results
demonstrate that the bifurcated chalcogen−hydrogen bonding
μ(S,N−H)Cl is prone to dimerization not only in the solid state
but also in solution.
1
Avance 400 MHz spectrometer, while 2D (1H, 13C-HSQC, H,13C-
HMBC) NMR correlation experiments were recorded on a Bruker
Avance III 500 MHz spectrometer. All NMR spectra were acquired in
CDCl3 or DMSO-d6 at 298K.
Synthetic Work. Synthesis of 11−14. A solution of 1 (20 mg, 5
mmol) in CH2Cl2 (3 mL) was added to any of the thiazol-2-amines
2−5 (10 mmol) placed in a 10 mL flask, and the mixture was stirred in
air at room temperature for 2−4 h. The reaction mixtures gradually
turned from pale yellow to intense lemon yellow, and solid (2−5)·HCl
precipitated. The formed solution was filtered and evaporated at 20−
25 °C to dryness, and then the solid residue was washed with Et2O
(three 1 mL portions) and dried in air at room temperature. Pure
CONCLUSIONS
■
In this work, we found that the PdII-mediated reaction of
CyNC with various thiazol-2-amines (2−4, 6−10) and
benzothiazol-2-amine (5) proceeds differently in comparison
to the respective reaction of XylNC,24a giving aminocarbene-
like complexes 11−14 (in the cases of thiazol-2-amines 2−4
I
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
complexes 11−14 were isolated by dissolution of the raw products in a
CH2Cl2 (2 mL)/Et2O (1.5 mL) mixture and then the resulting
solutions were subjected to crystallization on slow evaporation.
Synthesis of 15−19. A solution of 1 (20 mg, 5 mmol) in C2H4Cl2
(5 mL) was added to any of the thiazol-2-amines 6−10 (5 mmol)
placed in a 10 mL flask, and the mixture was stirred in air upon reflux
for 1−2 days. The reaction mixtures gradually turned from pale yellow
to intense orange, and the solid thiazol-2-amines were dissolved. In the
cases of 9 and 10, the final products 18 and 19 were precipitated as
colorless solids from the appropriate solutions. After cooling, the solid
residues were filtered off and 18 and 19 were then washed with diethyl
ether (three 1 mL portions) and dried in air at room temperature. The
reaction mixtures of 15−17 were evaporated at 20−25 °C to dryness,
and then the solid residues were washed with Et2O (three 1 mL
portions) and dried in air at room temperature. Pure complexes 15−
17 were isolated by dissolution of the formed residues in a CH2Cl2 (2
mL)/Et2O (1.5 mL) mixture, and then the resulting solutions were
subjected to crystallization on slow evaporation.
were used as starting point. The solvent effects were taken into
account using the SMD continuum solvation model by Truhlar et al.69
The Hessian matrix was calculated analytically for the optimized
structure in order to prove the location of correct minima (no
imaginary frequencies) and to estimate the thermodynamic parame-
ters, the latter being calculated at 25 °C. The topological analysis of
the electron density distribution with the help of the atoms in
molecules (AIM) method developed by Bader41 has been performed
by using the Multiwfn program (version 3.3.8).70 The Cartesian
atomic coordinates of the calculated equilibrium structures of 15 in the
gas phase and CHCl3 solution are given in Table S4 in the Supporting
Information.
Processing of CCDC Data. Processing of the Cambridge
Structure Database (v 5.38) was performed using the ConQuest
module (v 1.19). Only structures with bifurcated chalcogen−hydrogen
μ(Ch,E−H)Hal bonding with halogen atoms were included in the search
(Ch = S, Se, Te; Hal = F, Cl, Br, I; Table S1). The analysis for
μ(Ch,E−H)Hal was based on five parameters: viz., the distances Ch···X
(d1), H···X (d2), and E···X (d3) and angles Y(E)−Ch−X (a1) and E−
H−X (a2) (Figure 10). For S-containing systems the Ch···X and H···X
The pure complexes were obtained as yellow (11−14) or colorless
(15−19) solids and were characterized by microanalyses (C, H, N),
high-resolution ESI-MS, FTIR, TG/DTA, and 1D (1H, 13C{1H},
1
1
19F{1H}) and 2D (1H,1H-COSY, H,1H-NOESY, H,13C-HSQC, and
1H,13C-HMBC) NMR spectroscopy.
Characterization. Characterization data and 1H, 13C{H}, and
19F{1H} NMR spectra are included in the Supporting Information.
X-ray Structure Determination. Single crystals of 11 and 15−17
were grown by the slow evaporation of solvent mixtures (Et2O/
CH2Cl2 for 11, 15, and 17 and Et2O/CHCl3 for 16) at room
temperature. Single crystals of 19 were grown from CHCl3 at room
temperature during the reaction. The X-ray experiments were
conducted on a SuperNova, Dual, Cu at zero, Atlas diffractometer
(CuKα, λ = 1.54184) for 15 and on a Xcalibur, Eos diffractometer
(Mo Kα, λ = 0.71073) for 11, 16, 17, and 19. The crystals were kept at
100(2) K during data collection. Using Olex2,60 the structures were
solved with ShelXS using direct methods (11, 15, and 16) and with
Superflip using the Charge Flipping structure solution program (19),
and all structures were refined with the ShelXL refinement package
using least-squares minimization.61 The unit cell of 17 contains
disordered molecules of solvent (CH2Cl2), which were treated as a
diffuse contribution to the overall scattering without specific atom
positions by SQUEEZE/PLATON.62 The carbon-bound H atoms
were placed in calculated positions and were included in the
refinement in the “riding” model approximation, with Uiso(H) set to
1.5[Ueq(C)] and C−H 0.96 Å for the CH3 groups, with Uiso(H) set to
1.2[Ueq(C)] and C−H 0.97 Å for the CH2 groups and C−H 0.93 Å for
the CH groups, and Uiso(H) set to 1.2[Ueq(N)] and N−H 0.86 Å for
the NH groups. Empirical absorption correction was applied with the
CrysAlisPro63 program complex using spherical harmonics imple-
mented in the SCALE3 ABSPACK scaling algorithm.
Figure 10. Parameters taken for processing of relevant CCDC data.
distances were restricted by the sum of Rowland vdW radii and for Se
and Te systems by the sum of Bondi vdW radii. The Y(E)−Ch−X and
E−H−X angles was restricted to be greater than 150 and 110°,
respectively.
Only structures with determined 3D and with no error were
included in the search query. In addition to this, disordered structures
and powder structures were also excluded from the search. To ensure
that we only had high-quality structures, the R factorwhich
represents the agreement between the obtained crystallographic
model and the experimental diffraction datawas kept at ≤0.1.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.inorg-
chem.8b00190.
■
S
Computational Details. The Hirshfeld molecular surface was
Experimental details for the synthesis and character-
ization of the complexes, crystallographic and computa-
tional information, and NMR spectra (PDF)
generated by the CrystalExplorer 3.1 program64 on the basis of the
65
results of the X-ray study. The normalized contact distances, dnorm
,
based on the Bondi van der Waals radii,36 were mapped into the
Hirshfeld surface. In the color scale, negative values of dnorm are
visualized by a red color indicating contacts shorter than the sum of
van der Waals radii. The white color denotes intermolecular distances
close to van der Waals contacts with dnorm equal to zero. In turn,
contacts longer than the sum of van der Waals radii with positive dnorm
values are colored in blue.
Accession Codes
CCDC 1499892, 1535254, 1543620, and 1557909−1557910
contain the supplementary crystallographic data for this paper.
These data can be obtained free of charge via www.ccdc.ca-
m.ac.uk/data_request/cif, or by emailing data_request@ccdc.
cam.ac.uk, or by contacting The Cambridge Crystallographic
Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax:
+44 1223 336033.
The full geometry optimization in the gas phase and in CHCl3
solution and single-point calculations based on the experimental X-ray
geometry (quasi-solid-state approach) of 15 have been carried out at
the DFT level of theory using the M06 functional66 (this functional
was specifically developed to describe weak dispersion forces and
noncovalent interactions) with the help of the Gaussian-09 program
package.67 The calculations were performed using the quasi-relativistic
Stuttgart pseudopotential that described 28 core electrons and the
appropriate contracted basis sets68 for the palladium atoms and the 6-
31G* basis sets for other atoms. No symmetry restrictions have been
applied during the geometry optimization, and experimental X-ray data
AUTHOR INFORMATION
Corresponding Authors
*E-mail for V.P.B.: v.boiarskii@spbu.ru.
*E-mail for V.Y.K.: v.kukushkin@spbu.ru.
■
ORCID
Alexander S. Mikherdov: 0000-0002-6471-5158
J
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
(c) Servati Gargari, M.; Stilinovic,
́
V.; Bauza,
́
A.; Frontera, A.; McArdle,
Alexander S. Novikov: 0000-0001-9913-5324
Mikhail A. Kinzhalov: 0000-0001-5055-1212
Vadim Yu. Kukushkin: 0000-0002-2253-085X
P.; Van Derveer, D.; Ng, S. W.; Mahmoudi, G. Design of Lead(II)
Metal−Organic Frameworks Based on Covalent and Tetrel Bonding.
Chem. - Eur. J. 2015, 21, 17951−17958.
(7) Mahadevi, A. S.; Sastry, G. N. Cooperativity in Noncovalent
Interactions. Chem. Rev. 2016, 116, 2775−2825.
Notes
The authors declare no competing financial interest.
(8) (a) Mahadevi, A. S.; Sastry, G. N. Cation−π Interaction: Its Role
and Relevance in Chemistry, Biology, and Material Science. Chem. Rev.
2013, 113, 2100−2138. (b) Dougherty, D. A. Y. The Cation − π
Interaction. Acc. Chem. Res. 2013, 46, 885−893. (c) Wang, H.; Wang,
W.; Jin, W. J. σ-Hole Bond vs π-Hole Bond: A Comparison Based on
Halogen Bond. Chem. Rev. 2016, 116, 5072−5104. (d) Schottel, B. L.;
Chifotides, H. T.; Dunbar, K. R. Anion-π interactions. Chem. Soc. Rev.
2008, 37, 68−83.
ACKNOWLEDGMENTS
■
Support from the Russian Science Foundation (grant 14-43-
00017P) is gratefully acknowledged. Physicochemical studies
were performed at the Center for Magnetic Resonance, the
Center for Chemical Analysis and Materials Research, the
Center for Thermogravimetric and Calorimetric Research, and
the Center for X-ray Diffraction Studies (all belonging to Saint
Petersburg State University). A.S.N. is thankful to the joint
Saint Petersburg State University and Santander Bank program
for the opportunity to conduct a computational part of this
work during two months’ sabbatical on leave at Instituto
(9) (a) Yam, V. W.-W.; Au, V. K.-M.; Leung, S. Y.-L. Light-Emitting
Self-Assembled Materials Based on d8 and d10 Transition Metal
Complexes. Chem. Rev. 2015, 115, 7589−7728. (b) Sculfort, S.;
Braunstein, P. Intramolecular d10-d10 interactions in heterometallic
clusters of the transition metals. Chem. Soc. Rev. 2011, 40, 2741−2760.
(c) Eryazici, I.; Moorefield, C. N.; Newkome, G. R. Square-Planar
Pd(II), Pt(II), and Au(III) Terpyridine Complexes: Their Syntheses,
Physical Properties, Supramolecular Constructs, and Biomedical
Activities. Chem. Rev. 2008, 108, 1834−1895.
́
Superior Tecnico, Universidade de Lisboa (Lisbon, Portugal).
DEDICATION
■
Dedicated to Irina Petrovna Beletskaya (Full Member of RAS),
“Mother and Father of Russian organometallic catalysis”, on the
occasion of her jubilee.
(10) (a) Cisneros, G. A.; Wikfeldt, K. T.; Ojamae, L.; Lu, J.; Xu, Y.;
̈
́ ́
Torabifard, H.; Bartok, A. P.; Csanyi, G.; Molinero, V.; Paesani, F.
Modeling Molecular Interactions in Water: From Pairwise to Many-
Body Potential Energy Functions. Chem. Rev. 2016, 116, 7501−7528.
(b) Ch’ng, L. C.; Samanta, A. K.; Czako, G.; Bowman, J. M.; Reisler,
́
H. Experimental and Theoretical Investigations of Energy Transfer
and Hydrogen-Bond Breaking in the Water Dimer. J. Am. Chem. Soc.
2012, 134, 15430−15435.
REFERENCES
■
(1) Hobza, P.; Rezac, J. Introduction: Noncovalent Interactions.
Chem. Rev. 2016, 116, 4911−4912.
(2) (a) Kollman, P. A.; Allen, L. C. Theory of the hydrogen bond.
Chem. Rev. 1972, 72, 283−303. (b) Grabowski, S. J. What Is the
Covalency of Hydrogen Bonding? Chem. Rev. 2011, 111, 2597−2625.
(3) (a) Gilday, L. C.; Robinson, S. W.; Barendt, T. A.; Langton, M. J.;
Mullaney, B. R.; Beer, P. D. Halogen Bonding in Supramolecular
Chemistry. Chem. Rev. 2015, 115, 7118−7195. (b) Cavallo, G.;
Metrangolo, P.; Milani, R.; Pilati, T.; Priimagi, A.; Resnati, G.;
Terraneo, G. The Halogen Bond. Chem. Rev. 2016, 116, 2478−2601.
(c) Kolar, M. H.; Hobza, P. Computer Modeling of Halogen Bonds
and Other sigma-Hole Interactions. Chem. Rev. 2016, 116, 5155−
5187.
(11) (a) Wagner, J. R.; Lee, C. T.; Durrant, J. D.; Malmstrom, R. D.;
Feher, V. A.; Amaro, R. E. Emerging Computational Methods for the
Rational Discovery of Allosteric Drugs. Chem. Rev. 2016, 116, 6370−
6390. (b) Venditti, V.; Egner, T. K.; Clore, G. M. Hybrid Approaches
to Structural Characterization of Conformational Ensembles of
Complex Macromolecular Systems Combining NMR Residual Dipolar
Couplings and Solution X-ray Scattering. Chem. Rev. 2016, 116, 6305−
6322.
(12) (a) Chivers, T.; Laitinen, R. S. Tellurium: a maverick among the
chalcogens. Chem. Soc. Rev. 2015, 44, 1725−1739. (b) Cozzolino, A.
F.; Elder, P. J. W.; Vargas-Baca, I. A survey of tellurium-centered
secondary-bonding supramolecular synthons. Coord. Chem. Rev. 2011,
255, 1426−1438. (c) Ho, P. C.; Szydlowski, P.; Sinclair, J.; Elder, P. J.
W.; Kubel, J.; Gendy, C.; Lee, L. M.; Jenkins, H.; Britten, J. F.; Morim,
D. R.; Vargas-Baca, I. Supramolecular macrocycles reversibly
assembled by Te···O chalcogen bonding. Nat. Commun. 2016, 7,
11299. (d) Garrett, G. E.; Gibson, G. L.; Straus, R. N.; Seferos, D. S.;
Taylor, M. S. Chalcogen Bonding in Solution: Interactions of
Benzotelluradiazoles with Anionic and Uncharged Lewis Bases. J.
Am. Chem. Soc. 2015, 137, 4126−4133.
(13) (a) Wang, W.; Ji, B.; Zhang, Y. Chalcogen Bond: A Sister
Noncovalent Bond to Halogen Bond. J. Phys. Chem. A 2009, 113,
8132−8135. (b) Bauza, A.; Quinonero, D.; Deya, P. M.; Frontera, A.
Halogen bonding versus chalcogen and pnicogen bonding: a combined
Cambridge structural database and theoretical study. CrystEngComm
2013, 15, 3137−3144.
(14) (a) Geboes, Y.; De Vleeschouwer, F.; De Proft, F.; Herrebout,
W. Exploiting the σ-hole Concept: an Infrared and Raman based
characterization of the S···O Chalcogen Bond between 2,2,4,4-
Tetrafluoro-1,3-dithiethane and Dimethyl Ether. Chem. - Eur. J.
2017, 23, 17384−17392. (b) Peacock, H.; Luo, J.; Yamashita, T.;
Luccarelli, J.; Thompson, S.; Hamilton, A. D. Non-covalent S···O
interactions control conformation in a scaffold that disrupts islet
amyloid polypeptide fibrillation. Chem. Sci. 2016, 7, 6435−6439.
(c) Xiao, Q.; Sakurai, T.; Fukino, T.; Akaike, K.; Honsho, Y.; Saeki, A.;
Seki, S.; Kato, K.; Takata, M.; Aida, T. Propeller-Shaped Fused
Oligothiophenes: A Remarkable Effect of the Topology of Sulfur
Atoms on Columnar Stacking. J. Am. Chem. Soc. 2013, 135, 18268−
(4) (a) Gleiter, R.; Haberhauer, G.; Werz, D. B.; Rominger, F.;
Bleiholder, C. From Noncovalent Chalcogen−Chalcogen Interactions
to Supramolecular Aggregates: Experiments and Calculations. Chem.
Rev. 2018, DOI: 10.1021/acs.chemrev.7b00449. (b) Pascoe, D. J.;
Ling, K. B.; Cockroft, S. L. The Origin of Chalcogen-Bonding
Interactions. J. Am. Chem. Soc. 2017, 139, 15160−15167. (c) Mahmu-
dov, K. T.; Kopylovich, M. N.; Guedes da Silva, M. F. C.; Pombeiro, A.
J. L. Chalcogen bonding in synthesis, catalysis and design of materials.
Dalton Trans. 2017, 46, 10121−10138. (d) Zhao, H.; Gabbaï, F. P. A
bidentate Lewis acid with a telluronium ion as an anion-binding site.
Nat. Chem. 2010, 2, 984−990. (e) Bleiholder, C.; Werz, D. B.; Koppel,
H.; Gleiter, R. Theoretical investigations on chalcogen-chalcogen
interactions: What makes these nonbonded interactions bonding? J.
Am. Chem. Soc. 2006, 128, 2666−2674.
(5) (a) Bauza, A.; Mooibroek, T. J.; Frontera, A. The Bright Future of
Unconventional sigma/-Hole Interactions. ChemPhysChem 2015, 16,
2496−2517. (b) Scheiner, S. The Pnicogen Bond: Its Relation to
Hydrogen, Halogen, and Other Noncovalent Bonds. Acc. Chem. Res.
2013, 46, 280−288. (c) Zahn, S.; Frank, R.; Hey-Hawkins, E.;
Kirchner, B. Pnicogen Bonds: A New Molecular Linker? Chem. - Eur. J.
2011, 17, 6034−6038.
́
(6) (a) Mahmoudi, G.; Bauza, A.; Amini, M.; Molins, E.; Mague, J.
T.; Frontera, A. On the importance of tetrel bonding interactions in
lead(II) complexes with (iso)nicotinohydrazide based ligands and
several anions. Dalton Trans. 2016, 45, 10708−10716. (b) Mahmoudi,
́
G.; Bauza, A.; Frontera, A. Concurrent agostic and tetrel bonding
interactions in lead(II) complexes with an isonicotinohydrazide based
ligand and several anions. Dalton Trans. 2016, 45, 4965−4969.
K
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
18271. (d) Wang, X.-Y.; Jiang, W.; Chen, T.; Yan, H.-J.; Wang, Z.-H.;
Wan, L.-J.; Wang, D. Molecular evidence for the intermolecular S ··· S
interaction in the surface molecular packing motifs of a fused
thiophene derivative. Chem. Commun. 2013, 49, 1829−1831.
(15) Breugst, M.; von der Heiden, D.; Schmauck, J. Novel
Noncovalent Interactions in Catalysis: A Focus on Halogen,
Chalcogen, and Anion-pi Bonding. Synthesis 2017, 49, 3224−3236.
(16) (a) Jungbauer, S. H.; Huber, S. M. Cationic Multidentate
Halogen-Bond Donors in Halide Abstraction Organocatalysis: Catalyst
Optimization by Preorganization. J. Am. Chem. Soc. 2015, 137, 12110−
12120. (b) Jungbauer, S. H.; Walter, S. M.; Schindler, S.; Rout, L.;
Kniep, F.; Huber, S. M. Activation of a carbonyl compound by halogen
bonding. Chem. Commun. 2014, 50, 6281−6284. (c) He, W.; Ge, Y.-
C.; Tan, C.-H. Halogen-Bonding-Induced Hydrogen Transfer to C
N Bond with Hantzsch Ester. Org. Lett. 2014, 16, 3244−3247.
(d) Kniep, F.; Rout, L.; Walter, S. M.; Bensch, H. K. V.; Jungbauer, S.
H.; Herdtweck, E.; Huber, S. M. 5-Iodo-1,2,3-triazolium-based
multidentate halogen-bond donors as activating reagents. Chem.
Commun. 2012, 48, 9299−9301.
Bonding in Metal-Bound Alkylthiocyanates. Cryst. Growth Des. 2016,
16, 2979−2987.
(23) (a) Boyarskiy, V. P.; Bokach, N. A.; Luzyanin, K. V.; Kukushkin,
V. Y. Metal-Mediated and Metal-Catalyzed Reactions of Isocyanides.
Chem. Rev. 2015, 115, 2698−2779. (b) Boyarskiy, V. P.; Luzyanin, K.
V.; Kukushkin, V. Y. Acyclic diaminocarbenes (ADCs) as a promising
alternative to N-heterocyclic carbenes (NHCs) in transition metal
catalyzed organic transformations. Coord. Chem. Rev. 2012, 256,
2029−2056.
(24) (a) Mikherdov, A. S.; Kinzhalov, M. A.; Novikov, A. S.;
Boyarskiy, V. P.; Boyarskaya, I. A.; Dar’in, D. V.; Starova, G. L.;
Kukushkin, V. Y. Difference in Energy between Two Distinct Types of
Chalcogen Bonds Drives Regioisomerization of Binuclear
(Diaminocarbene)PdII Complexes. J. Am. Chem. Soc. 2016, 138,
14129−14137. (b) Bikbaeva, Z. M.; Ivanov, D. M.; Novikov, A. S.;
Ananyev, I. V.; Bokach, N. A.; Kukushkin, V. Y. Electrophilic−
Nucleophilic Dualism of Nickel(II) toward Ni···I Noncovalent
Interactions: Semicoordination of Iodine Centers via Electron Belt
and Halogen Bonding via σ-Hole. Inorg. Chem. 2017, 56, 13562−
13578. (c) Adonin, S. A.; Gorokh, I. D.; Novikov, A. S.; Abramov, P.
A.; Sokolov, M. N.; Fedin, V. P. Halogen Contacts-Induced Unusual
Coloring in Bi-III Bromide Complex: Anion-to-Cation Charge
Transfer via Br···Br Interactions. Chem. - Eur. J. 2017, 23, 15612−
15616. (d) Ivanov, D. M.; Novikov, A. S.; Ananyev, I. V.; Kirina, Y. V.;
Kukushkin, V. Y. Halogen bonding between metal centers and
halocarbons. Chem. Commun. 2016, 52, 5565−5568. (e) Novikov, A.
S.; Ivanov, D. M.; Avdontceva, M. S.; Kukushkin, V. Y. Diiodomethane
as a halogen bond donor toward metal-bound halides. CrystEngComm
2017, 19, 2517−2525. (f) Ivanov, D. M.; Kinzhalov, M. A.; Novikov,
A. S.; Ananyev, I. V.; Romanova, A. A.; Boyarskiy, V. P.; Haukka, M.;
Kukushkin, V. Y. H2C(X)-X···X- (X = CI, Br) Halogen Bonding of
Dihalomethanes. Cryst. Growth Des. 2017, 17, 1353−1362. (g) Ding,
X.; Tuikka, M. J.; Hirva, P.; Kukushkin, V. Y.; Novikov, A. S.; Haukka,
M. Fine-tuning halogen bonding properties of diiodine through
halogen-halogen charge transfer - extended [Ru(2,2’-bipyridine)(CO)-
2 × 2]···I2 systems (X = Cl, Br, I). CrystEngComm 2016, 18, 1987−
1995. (h) Ivanov, D. M.; Novikov, A. S.; Starova, G. L.; Haukka, M.;
Kukushkin, V. Y. A family of heterotetrameric clusters of chloride
species and halomethanes held by two halogen and two hydrogen
bonds. CrystEngComm 2016, 18, 5278−5286. (i) Mikhaylov, V. N.;
Sorokoumov, V. N.; Korvinson, K. A.; Novikov, A. S.; Balova, I. A.
Synthesis and Simple Immobilization of Palladium(II) Acyclic
Diaminocarbene Complexes on Polystyrene Support as Efficient
Catalysts for Sonogashira and Suzuki−Miyaura Cross-Coupling.
Organometallics 2016, 35, 1684−1697. (j) Serebryanskaya, T. V.;
Novikov, A. S.; Gushchin, P. V.; Haukka, M.; Asfin, R. E.; Tolstoy, P.
M.; Kukushkin, V. Y. Identification and H(D)-bond energies of C-
H(D)center dot center dot center dot Cl interactions in chloride-
haloalkane clusters: a combined X-ray crystallographic, spectroscopic,
and theoretical study. Phys. Chem. Chem. Phys. 2016, 18, 14104−
14112.
́
(17) (a) Benz, S.; Lopez-Andarias, J.; Mareda, J.; Sakai, N.; Matile, S.
Catalysis with Chalcogen Bonds. Angew. Chem., Int. Ed. 2017, 56,
812−815. (b) Benz, S.; Mareda, J.; Besnard, C.; Sakai, N.; Matile, S.
Catalysis with chalcogen bonds: neutral benzodiselenazole scaffolds
with high-precision selenium donors of variable strength. Chem. Sci.
2017, 8, 8164−8169. (c) Wonner, P.; Vogel, L.; Duser, M.; Gomes, L.;
̈
Kniep, F.; Mallick, B.; Werz, D. B.; Huber, S. M. Carbon-Halogen
Bond Activation by Selenium-Based Chalcogen Bonding. Angew.
Chem., Int. Ed. 2017, 56, 12009−12012.
(18) Molina, P.; Zapata, F.; Caballero, A. Anion Recognition
Strategies Based on Combined Noncovalent Interactions. Chem. Rev.
2017, 117, 9907−9972.
́
(19) (a) Barendt, T. A.; Docker, A.; Marques, I.; Felix, V.; Beer, P. D.
Selective Nitrate Recognition by a Halogen-Bonding Four-Station
[3]Rotaxane Molecular Shuttle. Angew. Chem., Int. Ed. 2016, 55,
11069−11076. (b) Zapata, F.; Caballero, A.; White, N. G.; Claridge, T.
́
D. W.; Costa, P. J.; Felix, V. t.; Beer, P. D. Fluorescent Charge-Assisted
Halogen-Bonding Macrocyclic Halo-Imidazolium Receptors for Anion
Recognition and Sensing in Aqueous Media. J. Am. Chem. Soc. 2012,
134, 11533−11541. (c) Robinson, S. W.; Mustoe, C. L.; White, N. G.;
Brown, A.; Thompson, A. L.; Kennepohl, P.; Beer, P. D. Evidence for
Halogen Bond Covalency in Acyclic and Interlocked Halogen-Bonding
Receptor Anion Recognition. J. Am. Chem. Soc. 2015, 137, 499−507.
(d) Walter, S. M.; Kniep, F.; Rout, L.; Schmidtchen, F. P.; Herdtweck,
E.; Huber, S. M. Isothermal Calorimetric Titrations on Charge-
Assisted Halogen Bonds: Role of Entropy, Counterions, Solvent, and
Temperature. J. Am. Chem. Soc. 2012, 134 (20), 8507−8512.
(20) (a) Benz, S.; Macchione, M.; Verolet, Q.; Mareda, J.; Sakai, N.;
Matile, S. Anion Transport with Chalcogen Bonds. J. Am. Chem. Soc.
2016, 138, 9093−9096. (b) Scheiner, S. Highly Selective Halide
Receptors Based on Chalcogen, Pnicogen, and Tetrel Bonds. Chem. -
Eur. J. 2016, 22, 18850−18858. (c) Garrett, G. E.; Carrera, E. I.;
Seferos, D. S.; Taylor, M. S. Anion recognition by a bidentate
chalcogen bond donor. Chem. Commun. 2016, 52, 9881−9884.
(d) Lim, J. Y. C.; Marques, I.; Thompson, A. L.; Christensen, K. E.;
(25) Moss, G. P.; Smith, P. A. S.; Tavernier, D. Glossary of Class
Names of Organic-Compounds and Reactive Intermediates Based on
Structure. Pure Appl. Chem. 1995, 67, 1307−1375.
Fel
́
ix, V.; Beer, P. D. Chalcogen Bonding Macrocycles and [2]-
(26) Kinzhalov, M. A.; Starova, G. L.; Boyarskiy, V. P. Interaction of
benzene-1,2-diamines with isocyanide complexes of palladium(II):
Insight into the mechanism. Inorg. Chim. Acta 2017, 455, 607−612.
(27) (a) Timofeeva, S. A.; Kinzhalov, M. A.; Valishina, E. A.;
Luzyanin, K. V.; Boyarskiy, V. P.; Buslaeva, T. M.; Haukka, M.;
Kukushkin, V. Y. Application of palladium complexes bearing acyclic
amino(hydrazido)carbene ligands as catalysts for copper-free Sonoga-
shira cross-coupling. J. Catal. 2015, 329, 449−456. (b) Kinzhalov, M.
A.; Luzyanin, K. V.; Boyarskiy, V. P.; Haukka, M.; Kukushkin, V. Y.
ADC-Based Palladium Catalysts for Aqueous Suzuki Miyaura Cross-
Coupling Exhibit Greater Activity than the Most Advantageous
Catalytic Systems. Organometallics 2013, 32, 5212−5223. (c) Kinzha-
lov, M. A.; Boyarskiy, V. P.; Luzyanin, K. V.; Dolgushin, F. M.;
Kukushkin, V. Y. Metal-mediated coupling of a coordinated isocyanide
and indazoles. Dalton Trans. 2013, 42, 10394−10397. (d) Anisimova,
Rotaxanes for Anion Recognition. J. Am. Chem. Soc. 2017, 139, 3122−
3133.
(21) (a) Feldblum, E. S.; Arkin, I. T. Strength of a bifurcated H bond.
Proc. Natl. Acad. Sci. U. S. A. 2014, 111, 4085−4090. (b) Schneider, H.
J. Binding Mechanisms in Supramolecular Complexes. Angew. Chem.,
Int. Ed. 2009, 48, 3924−3977. (c) Steiner, T. The Hydrogen Bond in
the Solid State. Angew. Chem., Int. Ed. 2002, 41, 48−76. (d) Rozas, I.;
Alkorta, I.; Elguero, J. Bifurcated Hydrogen Bonds: Three-Centered
Interactions. J. Phys. Chem. A 1998, 102, 9925−9932. (e) Aakeroy, C.
̈
B.; Rajbanshi, A.; Desper, J. Hydrogen-bond driven assembly of a
molecular capsule facilitated by supramolecular chelation. Chem.
Commun. 2011, 47, 11411−11413.
(22) Yandanova, E. S.; Ivanov, D. M.; Kuznetsov, M. L.; Starikov, A.
G.; Starova, G. L.; Kukushkin, V. Y. Recognition of S···CI Chalcogen
L
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
T. B.; Guedes da Silva, M. F. C.; Kukushkin, V. Y.; Pombeiro, A. J. L.;
Luzyanin, K. V. Metal-mediated coupling of amino acid esters with
isocyanides leading to new chiral acyclic aminocarbene complexes.
Dalton Trans. 2014, 43, 15861−15871. (e) Luzyanin, K. V.; Pombeiro,
A. J. L.; Haukka, M.; Kukushkin, V. Y. Coupling between 3-
Iminoisoindolin-1-ones and Complexed Isonitriles as a Metal-
Mediated Route to a Novel Type of Palladium and Platinum
Iminocarbene Species. Organometallics 2008, 27, 5379−5389.
(f) Chay, R. S.; Luzyanin, K. V.; Kukushkin, V. Y.; Guedes da Silva,
M. F. C.; Pombeiro, A. J. L. Novel Palladium-Aminocarbene Species
Derived from Metal-Mediated Coupling of Isonitriles and 1,3-
Diiminoisoindoline: Synthesis and Catalytic Application in Suzuki-
Miyaura Cross-Coupling. Organometallics 2012, 31, 2379−2387.
(g) Valishina, E. A.; Guedes da Silva, M. F. C.; Kinzhalov, M. A.;
Timofeeva, S. A.; Buslaeva, T. M.; Haukka, M.; Pombeiro, A. J. L.;
Boyarskiy, V. P.; Kukushkin, V. Y.; Luzyanin, K. V. Palladium-ADC
complexes as efficient catalysts in copper-free and room temperature
Sonogashira coupling. J. Mol. Catal. A: Chem. 2014, 395, 162−171.
(h) Kinzhalov, M. A.; Luzyanin, K. V.; Boyarskiy, V. P.; Haukka, M.;
Kukushkin, V. Y. Coupling of C-amino aza-substituted heterocycles
with an isocyanide ligand in palladium(II) complex. Russ. Chem. Bull.
2013, 62, 758−766.
(28) (a) Abraham, R. J.; Mobli, M. An NMR, IR and theoretical
investigation of 1H Chemical Shifts and hydrogen bonding in phenols.
Magn. Reson. Chem. 2007, 45, 865−877. (b) Haushalter, K. A.; Lau, J.;
Roberts, J. D. An NMR Investigation of the Effect of Hydrogen
Bonding on the Rates of Rotation about the C−N Bonds in Urea and
Thiourea. J. Am. Chem. Soc. 1996, 118, 8891−8896.
(29) (a) Martinez-Martinez, A. J.; Chicote, M. T.; Bautista, D.;
Vicente, J. Synthesis of Palladium(II), -(III), and -(IV) Complexes
with Acyclic Diaminocarbene Ligands. Organometallics 2012, 31,
3711−3719. (b) Wanniarachchi, Y. A.; Slaughter, L. M. One-step
assembly of a chiral palladium bis(acyclic diaminocarbene) complex
and its unexpected oxidation to a bis(amidine) complex. Chem.
Commun. 2007, 0, 3294−3296. (c) Tskhovrebov, A. G.; Luzyanin, K.
V.; Dogushin, F. M.; Guedes da Silva, M. F. C.; Pombeiro, A. J. L.;
Kukushkin, V. Y. Novel Reactivity Mode of Metal Diaminocarbenes:
Palladium(II)-Mediated Coupling between Acyclic Diaminocarbenes
and Isonitriles Leading to Dinuclear Species. Organometallics 2011, 30,
3362−3370.
(30) Kitano, Y.; Hori, T. Structure of cis-Dichlorobis(Cyclohexyl
Isocyanide) Palladium(II). Acta Crystallogr., Sect. B: Struct. Crystallogr.
Cryst. Chem. 1981, 37, 1919−1921.
(31) Perreault, D.; Drouin, M.; Michel, A.; Harvey, P. D.
Relationships between Metal-Metal Force-Constants and Metal-
Metal Separations for Ag2 and Pd2 Systems - Crystal and
Molecular-Structures of Ag2(Dmb)2 × 2 (X = Cl, Br, I Dmb = 1,8-
Diisocyano-P-Menthane) And Cis-Pd(Cnc(CH3)3)2Cl2 Complexes.
Inorg. Chem. 1993, 32, 1903−1912.
(32) Drouin, M.; Perreault, D.; Harvey, P. D.; Michel, A. Quasi-One-
Dimensional Structure of Cis-Dichlorobis(2,6-Dimethylphenyl Iso-
cyanide)-Palladium(Ii), [Pd(2,6-(CH3)2C6H3NC)2Cl2]. Acta Crys-
tallogr., Sect. C: Cryst. Struct. Commun. 1991, 47, 752−754.
(33) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Taylor, R. Tables of Bond Lengths Determined by X-Ray and
Neutron-Diffraction 0.1. Bond Lengths in Organic-Compounds. J.
Chem. Soc., Perkin Trans. 2 1987, 2, S1−S19.
(34) Luzyanin, K. V.; Guedes da Silva, M. F. C.; Kukushkin, V. Y.;
Pombeiro, A. J. L. First example of an imine addition to coordinated
isonitrile. Inorg. Chim. Acta 2009, 362, 833−838.
(35) Moncada, A. I.; Manne, S.; Tanski, J. M.; Slaughter, L. M.
Modular chelated palladium diaminocarbene complexes: Synthesis,
characterization, and optimization of catalytic Suzuki-Miyaura cross-
coupling activity by ligand modification. Organometallics 2006, 25,
491−505.
expected from van der Waals radii. J. Phys. Chem. 1996, 100, 7384−
7391.
(38) (a) Cozzolino, A. F.; Vargas-Baca, I.; Mansour, S.;
Mahmoudkhani, A. H. The nature of the supramolecular association
of 1,2,5-chalcogenadiazoles. J. Am. Chem. Soc. 2005, 127, 3184−3190.
(b) Burling, F. T.; Goldstein, B. M. Computational Studies of
Nonbonded Sulfur Oxygen and Selenium Oxygen Interactions in the
Thiazole and Selenazole Nucleosides. J. Am. Chem. Soc. 1992, 114,
2313−2320. (c) Rosenfield, R. E.; Parthasarathy, R.; Dunitz, J. D.
Directional Preferences of Nonbonded Atomic Contacts with Divalent
Sulfur 0.1. Electrophiles and Nucleophiles. J. Am. Chem. Soc. 1977, 99,
4860−4862.
(39) Allinger, N. L.; Zhou, X. F.; Bergsma, J. Molecular Mechanics
Parameters. J. Mol. Struct.: THEOCHEM 1994, 312, 69−83.
(40) Arunan, E.; Desiraju, G. R.; Klein, R. A.; Sadlej, J.; Scheiner, S.;
Alkorta, I.; Clary, D. C.; Crabtree, R. H.; Dannenberg, J. J.; Hobza, P.;
Kjaergaard, H. G.; Legon, A. C.; Mennucci, B.; Nesbitt, D. J. Definition
of the hydrogen bond (IUPAC Recommendations 2011). Pure Appl.
Chem. 2011, 83, 1637−1641.
(41) Bader, R. F. W. A Quantum-Theory of Molecular-Structure and
Its Applications. Chem. Rev. 1991, 91, 893−928.
(42) Novikov, A. S.; Kuznetsov, M. L.; Pombeiro, A. J. L. Theory of
the Formation and Decomposition of N-Heterocyclic Amino-
oxycarbenes through Metal-Assisted 2 + 3 -Dipolar Cycloaddition/
Retro-Cycloaddition. Chem. - Eur. J. 2013, 19, 2874−888.
́
(43) Johnson, E. R.; Keinan, S.; Mori-Sanchez, P.; Contreras-García,
J.; Cohen, A. J.; Yang, W. Revealing Noncovalent Interactions. J. Am.
Chem. Soc. 2010, 132, 6498−6506.
(44) Espinosa, E.; Molins, E.; Lecomte, C. Hydrogen bond strengths
revealed by topological analyses of experimentally observed electron
densities. Chem. Phys. Lett. 1998, 285, 170−173.
(45) Vener, M. V.; Egorova, A. N.; Churakov, A. V.; Tsirelson, V. G.
Intermolecular hydrogen bond energies in crystals evaluated using
electron density properties: DFT computations with periodic
boundary conditions. J. Comput. Chem. 2012, 33, 2303−2309.
(46) Chai, J. D.; Head-Gordon, M. Long-range corrected hybrid
density functionals with damped atom-atom dispersion corrections.
Phys. Chem. Chem. Phys. 2008, 10, 6615−6620.
(47) Espinosa, E.; Alkorta, I.; Elguero, J.; Molins, E. From weak to
strong interactions: A comprehensive analysis of the topological and
energetic properties of the electron density distribution involving X-H
center dot center dot center dot F-Y systems. J. Chem. Phys. 2002, 117,
5529−5542.
(48) Glendening, E. D.; Landis, C. R.; Weinhold, F. Natural bond
orbital methods. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2012, 2, 1−
42.
́
(49) (a) Sanchez-Sanz, G.; Trujillo, C. Improvement of Anion
Transport Systems by Modulation of Chalcogen Interactions: The
influence of solvent. J. Phys. Chem. A 2018, 122, 1369−1377.
(b) Sanchez-Sanz, G.; Trujillo, C.; Alkorta, I.; Elguero, J. Weak
interactions between hypohalous acids and dimethylchalcogens. Phys.
Chem. Chem. Phys. 2012, 14, 9880−889.
(50) Blanksby, S. J.; Ellison, G. B. Bond dissociation energies of
organic molecules. Acc. Chem. Res. 2003, 36, 255−263.
(51) (a) Diop, M. B.; Diop, L.; Oliver, A. G. IUCr, Crystal structure
of di-chlorido-bis-(dimethyl N-cyano-dithio-imino-carbonate)zinc.
Acta Crystallogr., Sect. E: Crystallogr. Commun. 2016, 72, 417−419.
(b) Diop, M. B.; Diop, L.; Oliver, A. G. Crystal structure of
dichloridobis(dimethyl N-cyanodithioiminocarbonate)cobalt(II). Acta
Crystallogr., Sect. E: Crystallogr. Commun. 2016, 72, 66−68. (c) Abedi,
A.; Safari, N.; Amani, V.; Khavasi, H. R. Indium(III) complexes
containing bithiazole derivatives, chloride, methanol, and dimethyl
sulfoxide: X-ray studies, spectroscopic characterization, and thermal
analyses. J. Coord. Chem. 2012, 65, 325−338. (d) Zhang, Y. H.; Wang,
J.; Zheng, L. L.; Hu, S.; Lin, Z. J.; Tong, M. L. Structural diversity and
reactivity of d(10) metal-(4-pyridylthio)acetate system. Chin. Sci. Bull.
2009, 54, 4277−4284. (e) Jin, S.; Wang, D. Syntheses and molecular
structures of four inorganic−organic hybrid compounds from N-
containing aromatic bases and perchlorometallates of Zn, Cu, Sn, and
(36) Bondi, A. Van Der Waals Volumes + Radii. J. Phys. Chem. 1964,
68, 441−451.
(37) Rowland, R. S.; Taylor, R. Intermolecular nonbonded contact
distances in organic crystal structures: Comparison with distances
M
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Fe. J. Coord. Chem. 2012, 65, 3188−3204. (f) Garcia-Hernandez, Z.;
Flores-Parra, A.; Grevy, J. M.; Ramos-Organillo, A.; Contreras, R. 2-
Aminobenzothiazole phosphorus amides: Molecular and supra-
molecular structures, hydrogen bonds and sulfur donor-acceptor
interactions. Polyhedron 2006, 25, 1662−1672. (g) Díaz, J. R. A.; Camí,
arylethanones. Angew. Chem., Int. Ed. 2013, 52 (44), 11632−11636.
(b) Zheng, S. L.; Zhong, Q.; Jiang, Q.; Mottamal, M.; Zhang, Q.; Zhu,
N. J.; Burow, M. E.; Worthylake, R. A.; Wang, G. D. Discovery of a
Series of Thiazole Derivatives as Novel Inhibitors of Metastatic Cancer
Cell Migration and Invasion. ACS Med. Chem. Lett. 2013, 4, 191−196.
(60) Dolomanov, O.; Bourhis, L.; Gildea, R.; Howard, J.; Puschmann,
H. OLEX2: a complete structure solution, refinement and analysis
program. J. Appl. Crystallogr. 2009, 42, 339−341.
́
G. E.; Gonzalez, M. L.; Pedregosa, J. C.; Vega, D. R. Two Novel
Potential Anticonvulsant Salts of 5-Amino-2-Sulfonamide-1,3,4-
Thiadiazole. J. Chem. Crystallogr. 2011, 41, 1114−1119. (h) Owczarzak,
A. M.; Kubicki, M.; Kourkoumelis, N.; Hadjikakou, S. K. Stabilization
of poly-iodides: structural influences of the cationic disulfides of 2-
mercapto-3,4,5,6-tetrahydro-pyrimidine and 2-mercatpo-pyrimidine.
RSC Adv. 2012, 2, 2856−2867. (i) Biesiada, M.; Kourkoumelis, N.;
Kubicki, M.; Owczarzak, A. M.; Balas, V.; Hadjikakou, S. K.
Fundamental chemistry of iodine. The reaction of di-iodine towards
thiourea and its methyl-derivative: formation of aminothiazoles and
aminothiadiazoles through dicationic disulfides. Dalton Trans. 2014,
43, 4790−4806. (j) Aoki, K.; Tokuno, T.; Takagi, K.; Hirose, Y.; Suh,
I.-H.; Adeyemo, A. O.; Williams, G. N. The [PtIV Cl6]2−/thiamine
system. Crystal structures of (H-thiamine)[PtCl6]·H2O and (H-
thiamine)2[PtCl6]Cl2·2H2O: hostguest-like anion coordination.
Inorg. Chim. Acta 1993, 210, 17−25.
(61) Sheldrick, G. M. A short history of SHELX. Acta Crystallogr.,
Sect. A: Found. Crystallogr. 2008, 64, 112−122.
(62) Spek, A. L. PLATON SQUEEZE: a tool for the calculation of
the disordered solvent contribution to the calculated structure factors.
Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71 (1), 9−18.
(63) CrysAlisPro, 1.171.36.20; Agilent Technologies, 2012.
(64) (a) Wolff, S. K.; Grimwood, D. J.; McKinnon, J. J.; Turner, M.
J.; Jayatilaka, D.; Spackman, M. A. CrystalExplorer, Version 3.1;
University of Western Australia, 2012. (b) Spackman, M. A.; Jayatilaka,
D. Hirshfeld surface analysis. CrystEngComm 2009, 11, 19−32.
(65) McKinnon, J. J.; Jayatilaka, D.; Spackman, M. A. Towards
quantitative analysis of intermolecular interactions with Hirshfeld
surfaces. Chem. Commun. 2007, 0, 3814−3816.
(66) Zhao, Y.; Truhlar, D. G. The M06 suite of density functionals
for main group thermochemistry, thermochemical kinetics, non-
covalent interactions, excited states, and transition elements: two new
functionals and systematic testing of four M06-class functionals and 12
other functionals. Theor. Chem. Acc. 2008, 120, 215−241.
́
(52) Bartolome, C.; Carrasco-Rando, M.; Coco, S.; Cordovilla, C.;
Martín-Alvarez, J. M.; Espinet, P. Luminescent Gold(I) Carbenes from
2-Pyridylisocyanide Complexes: Structural Consequences of Intra-
molecular versus Intermolecular Hydrogen-Bonding Interactions.
Inorg. Chem. 2008, 47, 1616−1624.
(67) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci,
B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H.
P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.;
Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima,
T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A.;
Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin,
N. K.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.;
Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega,
N.; Millam, J. M.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.;
Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.;
Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.;
Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.;
Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, J.; Foresman,
B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian 09, Revision C.01;
Gaussian, Inc., Wallingford, CT, 2010.
(53) (a) Tomasi, J. Selected features of the polarizable continuum
model for the representation of solvation. Wiley Interdiscip. Rev.:
Comput. Mol. Sci. 2011, 1, 855−867. (b) Mennucci, B. Polarizable
continuum model. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2012, 2,
386−404. (c) Jinich, A.; Rappoport, D.; Dunn, I.; Sanchez-Lengeling,
B.; Olivares-Amaya, R.; Noor, E.; Bar Even, A.; Aspuru-Guzik, A.
Quantum Chemical Approach to Estimating the Thermodynamics of
Metabolic Reactions. Sci. Rep. 2015, 4, 7022.
(54) (a) Suarez, D.; Diaz, N. Direct methods for computing single-
molecule entropies from molecular simulations. Wiley Interdiscip. Rev.:
Comput. Mol. Sci. 2015, 5, 1−26. (b) Zhou, H. X.; Gilson, M. K.
Theory of Free Energy and Entropy in Noncovalent Binding. Chem.
Rev. 2009, 109, 4092−4107. (c) Biedermann, F.; Schneider, H. J.
Experimental Binding Energies in Supramolecular Complexes. Chem.
Rev. 2016, 116, 5216−5300.
(55) Kinzhalov, M. A.; Timofeeva, S. A.; Luzyanin, K. V.; Boyarskiy,
V. P.; Yakimanskiy, A. A.; Haukka, M.; Kukushkin, V. Y. Palladium(II)-
Mediated Addition of Benzenediamines to Isocyanides: Generation of
Three Types of Diaminocarbene Ligands Depending on the Isomeric
Structure of the Nucleophile. Organometallics 2016, 35, 218−228.
(56) (a) Pastor, A.; Martinez-Viviente, E. NMR spectroscopy in
coordination supramolecular chemistry: A unique and powerful
methodology. Coord. Chem. Rev. 2008, 252, 2314−2345. (b) Maugeri,
L.; Asencio-Hernandez, J.; Lebl, T.; Cordes, D. B.; Slawin, A. M. Z.;
Delsuc, M. A.; Philp, D. Neutral iodotriazoles as scaffolds for stable
halogen-bonded assemblies in solution. Chem. Sci. 2016, 7, 6422−
6428.
(68) Andrae, D.; Haussermann, U.; Dolg, M.; Stoll, H.; Preuss, H.
Energy-Adjusted Abinitio Pseudopotentials for the 2nd and 3rd Row
Transition-Elements. Theor. Chim. Acta 1990, 77, 123−141.
(69) Marenich, A. V.; Cramer, C. J.; Truhlar, D. G. Universal
Solvation Model Based on Solute Electron Density and on a
Continuum Model of the Solvent Defined by the Bulk Dielectric
Constant and Atomic Surface Tensions. J. Phys. Chem. B 2009, 113,
6378−6396.
(70) Lu, T.; Chen, F. W. Multiwfn: A multifunctional wavefunction
analyzer. J. Comput. Chem. 2012, 33, 580−592.
(57) (a) Macchioni, A.; Ciancaleoni, G.; Zuccaccia, C.; Zuccaccia, D.
Determining accurate molecular sizes in solution through NMR
diffusion spectroscopy. Chem. Soc. Rev. 2008, 37, 479−489.
(b) Bellachioma, G.; Ciancaleoni, G.; Zuccaccia, C.; Zuccaccia, D.;
Macchioni, A. NMR investigation of non-covalent aggregation of
coordination compounds ranging from dimers and ion pairs up to
nano-aggregates. Coord. Chem. Rev. 2008, 252, 2224−2238. (c) Cohen,
Y.; Avram, L.; Frish, L. Diffusion NMR spectroscopy in supra-
molecular and combinatorial chemistry: An old parameter - New
insights. Angew. Chem., Int. Ed. 2005, 44, 520−554.
(58) Sivchik, V. V.; Grachova, E. V.; Melnikov, A. S.; Smirnov, S. N.;
Ivanov, A. Y.; Hirva, P.; Tunik, S. P.; Koshevoy, I. O. Solid-State and
Solution Metallophilic Aggregation of a Cationic Pt(NCN)L (+)
Cyclometalated Complex. Inorg. Chem. 2016, 55, 3351−3363.
(59) (a) Chen, J.; Liu, D.; Butt, N.; Li, C.; Fan, D.; Liu, Y.; Zhang, W.
Palladium-Catalyzed Asymmetric Hydrogenation of α-Acyloxy-1-
N
DOI: 10.1021/acs.inorgchem.8b00190
Inorg. Chem. XXXX, XXX, XXX−XXX