Triphenyltin(iv) adducts of diphosphoryl ligands: Structural, electronic and energy aspects from X-ray crystallography and theoretical calculations

Article abstract of DOI:10.1039/c4ra12925c

Some triphenyltin(iv) adducts with a family of diphosphoryl ligands, RR′P(O)-X-P(O)RR′ (R = OPh, Ph, R′ = R, An (aniline)) and X = 1,4-OC₆H₄O, 1,4-OC₆H₄NH, 1,4-NHC₆H₄NH 1,4-(NHCH₂)₂C₆H₄, 1,3-(NHCH₂)₂C₆H₄ and piperazine have been synthesized and characterized by IR and NMR spectroscopy. X-Ray crystallography reveals that the structure of these complexes comprises a binuclear arrangement with two SnPh₃Cl moieties linked via the bridging P(O)-X-P(O) ligands. The influence of the ligand structures on the organization of the crystal structures and the coordination interactions are discussed. Studies of the crystal packing reveal NH...Cl, CH...Cl or CH...O hydrogen bonding interactions, as a function of the X or R groups, to be the main factor controlling the supramolecular architecture in this series of complexes. Based on the results from quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses, Sn-ligand interactions are found to be mainly electrostatic (donor-acceptor-like with charge transfer from the phosphoryl donors to the tin atoms). The stronger coordination bonds are found in the complexes containing Ph substituents with aliphatic spacers, in agreement with the experimental evidence. Binuclear arrangements instead of polymeric or chelating systems may be attributed to the steric demands of SnPh₃Cl, regardless of the ligand structures.

Full text of DOI:10.1039/c4ra12925c

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Triphenyltin(IV) adducts of diphosphoryl ligands:
structural, electronic and energy aspects from
X-ray crystallography and theoretical calculations†
a
Cite this: RSC Adv., 2015, 5, 17482
K. Gholivand, A. Gholami,a A. A. V. Ebrahimi,a S. T. Abolghasemi,a M. D. Esrafili,b
*
F. T. Fadaeic and K. J. Schenkc
Some triphenyltin(IV) adducts with a family of diphosphoryl ligands, RR0P(O)–X–P(O)RR0 (R ¼ OPh, Ph,
R0
¼
R, An (aniline)) and
X
¼
1,4-OC6H4O, 1,4-OC6H4NH, 1,4-NHC6H4NH 1,4-(NHCH2)2C6H4,
1,3-(NHCH2)2C6H4 and piperazine have been synthesized and characterized by IR and NMR
spectroscopy. X-Ray crystallography reveals that the structure of these complexes comprises a binuclear
arrangement with two SnPh3Cl moieties linked via the bridging P(O)–X–P(O) ligands. The influence of
the ligand structures on the organization of the crystal structures and the coordination interactions are
discussed. Studies of the crystal packing reveal NH/Cl, CH/Cl or CH/O hydrogen bonding
interactions, as a function of the X or R groups, to be the main factor controlling the supramolecular
architecture in this series of complexes. Based on the results from quantum theory of atoms in
molecules (QTAIM) and natural bond orbital (NBO) analyses, Sn–ligand interactions are found to be
mainly electrostatic (donor–acceptor-like with charge transfer from the phosphoryl donors to the tin
atoms). The stronger coordination bonds are found in the complexes containing Ph substituents with aliphatic
spacers, in agreement with the experimental evidence. Binuclear arrangements instead of polymeric or
chelating systems may be attributed to the steric demands of SnPh3Cl, regardless of the ligand structures.
Received 22nd October 2014
Accepted 28th January 2015
DOI: 10.1039/c4ra12925c
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elucidate the relationship between the catalyst structure and its
selectivity and reactivity.
Introduction
From the above consideration, in connection with our
current interest in the coordination of phosphoramidates,6–11
we have further investigated the ligand behaviour of some
bidentate P(O)–X–P(O) ligands toward SnPh3Cl. Our interest in
this unique class of ligands stems from the systematic control
of stereoelectronic factors by subtle manipulation of the central
part (X), as well as terminal phosphorus substituents (R) in
order to study the inuence on the structure and properties of
the resulting complexes. It has been shown for phosphoryl
ligands of the type R1R2R3P]O that the donor character of the
phosphoryl group is a function of the R groups (R ¼ alkyl, aryl,
halogen, dialkylamino, alkoxy, etc.).12 From the structural point
of view, the modication of the P(O)–X–P(O) ligand-backbone
might be promising for supramolecular design because an
appropriate combination of length and rigidity of the central X-
moiety would allow control of the separation of the phosphoryl
donor groups and, consequently, the coordination pattern.13
Although, there are a number of reports on molecular
structures containing Sn–O–P fragments,14 a survey of the
literature reveals only a few publications10–12,15 on the nature of
tin–ligand interactions. We have not found any precise study on
the effect of all non-covalent interactions (including coordi-
nating linkages and intermolecular interactions) on the struc-
ture of organotin(IV) complexes with diphosphoryl ligands.
Organotin(IV) compounds are the subject of intensive studies
owing to their broad biological and industrial applications.1,2 In
addition, an application as structural blocks for the synthesis of
supramolecular coordination compounds has excited a new wave
of interest in the coordination chemistry of organotin(IV)
compounds.3 Phosphoryl-containing compounds have been used
as effective coordinating agents in tin chemistry.4 Tin complexes of
diphosphoryl ligands are also assumed to be important due to the
recent reports on a series of chiral-phosphoramides which use
these complexes as homogeneous catalysts in the enantioselective
allylation of allyltrichlorosilanes.5 Thus, understanding of the
phosphoramide–Lewis acid complex structure is crucial to
aDepartment of Chemistry, Faculty of Basic Sciences, Tarbiat Modares University, P.O.
Box 14115-175, Tehran, Iran. E-mail: gholi_kh@modares.ac.ir; Fax: +98-021-
88009730; Tel: +98-21-82884422
bLaboratory of Theoretical Chemistry, Department of Chemistry, University of
Maragheh, Maragheh, Iran
c
´
´ ´
Ecole Polytechnique Federale de Lausanne, CCC-IPSB, Le Cubotron Dorigny, 1015
Lausanne, Switzerland
† Electronic supplementary information (ESI) available: The crystal data and the
details of the X-ray analysis, selected bond lengths, bond angles, hydrogen
bonding data for the ligand 6Ph and computational data for fully optimized
structures. CCDC 990940–990945. For ESI and crystallographic data in CIF or
other electronic format see DOI: 10.1039/c4ra12925c
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˚
Accordingly we have carried out a comparative study on tri- 2.1215(19) to 2.1436(10) A) lie in the range corresponding to
18
˚
phenyltin(IV) adducts with a series of bidentate ligands pos- normal covalent radii (2.15 A). Sn–Cl bonds are also covalent
sessing rigid and exible frameworks with general formula interactions (normal covalent radii 2.37–2.60 A),19 while the Sn–
˚
RR0P(O)–X–P(O)RR0 where R ¼ OPh, Ph, R0 ¼ R, An (aniline) and O bonds are in accordance with the coordinate bond.
X
¼
1,4-OC6H4O, 1,4-OC6H4NH, 1,4-(NHCH2)2C6H4, 1,3-
P]O bond lengths decrease in order: C6Ph > C2Ph > C4NOPh >
(NHCH2)2C6H4 and piperazine (Scheme 1). Reaction of all the C5OPh > C1OPh, according to increasing P]O vibrational
ligands with Ph3SnCl afforded binuclear organotin(IV) adducts. frequencies. The P]O bond elongation is in almost linear
All compounds were characterized by IR and NMR (1H, 31P and correlation with shortening Sn–O bonds. Since the longest P]O
119Sn) spectroscopy and the structures of ligand 6Ph and ve distance is related to C6Ph and C2Ph, the phosphoryl groups in
complexes C1OPh, C2Ph, C4NOPh, C5OPh and C6Ph were determined these compounds were expected to have the highest polariz-
by X-ray crystallography. The structural, electronic, bonding ability and interaction to tin(IV). However, the shortest Sn–O
and energy aspects of Sn–O bonding for all compounds and also distance belongs to C4NOPh. Comparing the behaviour of these
other non-covalent intermolecular interactions for crystalline complexes in solution and gas phase reveals that the Sn–ligand
structures were investigated using density functional theory interactions are stronger for C6Ph and C2Ph than C4NOPh (see
(DFT) calculations.
section Spectroscopic characterization). Therefore, the unex-
pected Sn–O distances in C4NOPh may be considered as a result
of the packing effects and intermolecular interactions. Along
with the Sn–O bond shortening, the Sn–Cl bonds become
progressively longer. This can be viewed as a result of a greater
trans inuence of the bridging ligand related to its stronger
donating properties.
In the case of C2Ph, the ligand molecule lie on an inversion
center; so the positions of the nitrogen atom of the NH group
and the oxygen atom –O(2)– almost coincide. As a result, in the
independent part of the molecule – half of it – these groups are
disordered by two positions with equal occupancies 0.5 : 0.5.
This is why the P]O, Sn–O and Sn–Cl bond lengths for the two
different moieties of this complex are the same.
Results and discussion
Structural analysis using X-ray crystallography
Molecular structures. A view of the molecular structures as
ORTEP is shown in Fig. 1. The crystallographic data and a
summary of the most relevant bond distances and angles are
listed in Tables S1† and 1, respectively.
As shown in Fig. 1, the structures of complexes are quite
similar. They comprise binuclear arrangement with two
SnPh3Cl moieties linked via the bridging diphosphoryl ligands.
The bidentate ligands have their P]O groups in an anti-
conformation as they do in their uncoordinated form.16,17
The coordination polyhedra around tins can be described as
slightly distorted trigonal bipyramids with the three phenyl
carbon atoms occupying the equatorial positions and the
chlorine atom and the phosphoryl group at the apices (best seen
in C2Ph). The trans angles found around the metal are in the
range of 176.60(8)–179.48(4)ꢀ, while the sum of the angles
subtended at tin in the trigonal girdle are in the range of 359.2–
360ꢀ. The bonding parameters are in a good agreement with the
values found for similar linkages in the reported triphenyltin(IV)
complexes of phosphoryl ligands.4a,11 Sn–C distances (from
A comparison between the crystal structures of C6Ph and its
ligand, 6Ph, reveals that by coordinating the ligand to Sn, the
˚
P]O bonds get longer (about 0.012 A). Lengthening of the P]O
bond is simply described by polarization of the phosphoryl
group in the electrostatic eld of the tin(IV) atom. On the other
˚
hand, we notice that the P–N bonds are shortened about 0.014 A
in the complex C6Ph, consistent with the increase of P–N
stretching frequencies upon complexation.
Crystal packing. The crystal structure of the ligand 6Ph
contains hydrogen-bonded [001] chains generated by the
O–Hw/OP]O interactions (Fig. 2a). Interestingly, water mole-
cules between two adjacent diphosphoryl units function as
bifurcated H-donors to the P]O groups, forming eight-
membered (OP]O/H–O–H/OP]O/H–O–H) rings. These
interactions are established with different donor–acceptor
˚
˚
distances of 2.762(7) A and 2.773(7) A (Table S2†). Moreover,
each water molecule is involved (this time as an acceptor) in
other H-bonds with protons of Ph rings from other molecular
units. Besides the hydrogen bonds, the packing of 6Ph is further
stabilized by weaker intermolecular C–H/p interactions
between the neighbouring 1D polymers ꢀ(C10–H10/Cg: dH/Cg
˚
˚
¼ 2.821 A, dC/Cg ¼ 3.770(4) A, q ¼ 169.0 : Cg is the centroid of
Ph ring), along a-axis. As a result of these intermolecular
interactions, 3D supramolecular structures are generated in the
structure (Fig. 2b).
The presence of Sn–Cl moieties in the complex C6Ph leads to
the formation of intermolecular CH/Cl non-classical hydrogen
bonds building up [010] chains of tin(IV) adducts (Table 2 and
Fig. 3). The neighbouring chains are linked by CH/p
Scheme 1 Schematic presentation of diphosphoryl ligands.
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Fig. 1 Representation of isostructural complexes C1OPh, C2Ph, C4NOPh, C5OPh and C6Ph and ligand 6Ph (50% probability level). Hydrogen atoms
are omitted for clarity.
˚
˚
interactions (C4–H4/Cg: dH/Cg ¼ 2.868 A, dC/Cg ¼ 3.628(3) A, bonds. Here, a 2D structure, directed along the ac-plane, has been
q ¼ 137.82ꢀ: Cg is the centroid of Ph ring of the ligand). Weaker generated through equal CH/OR linkages (Table 2 and Fig. 5). As
CH/p and CH/HC interactions are also the driving force in mentioned for C2Ph, the rigid spacer of the ligand; because of steric
generating a 3D network in C6Ph
.
hindrance; are not involved in any close contact.
The same kind of interactions in the crystal lattice of C2Ph
In contrast, the existence of moderate NX–H/Cl hydrogen
creates a 2D network. Indeed, each complex is associated with four bonds in rather exible structures C5OPh and C4NOPh reveals that
adjacent complexes through equal CH/Cl linkages (Fig. 4), giving the NX–H groups (NH groups of the spacer) play an important
a two-dimensional arrangement. Besides, a [010] chain of tin role in directing their crystal packing. In the structure C4NOPh
adducts is distinguished by CH/p interactions between Ph (Fig. 6), the intermolecular NX–H/Cl interactions link the
groups on the SnPh3 moieties of the two neighbouring units discrete molecular into [001] chains (Table 2). These chains are
ꢀ
˚
˚
(C18–H18/Cg: dH/Cg ¼ 3.079 A, dC/Cg ¼ 3.609(2) A, q ¼ 116.80 : further reinforced by NRH/p and also weaker NXH/p
˚
˚
Cg is the centroid of Ph ring of the tin moiety). Other weak CH/p interactions (N1–H1N/Cg: dH/Cg ¼ 3.239 A, dN/Cg ¼ 3.939(5) A,
interactions are also contributed in stabilizing of the 2D aggrega- q ¼ 158.6ꢀ; N2–H2N/Cg: dH/Cg ¼ 2.837 A, dN/Cg ¼ 3.699(5) A,
tions. Notably, disordered NX–H groups; on the rigid central part; q ¼ 165.8ꢀ: Cg is the centroid of the same neighbouring tin-Ph
O–C6H4–NH; don't participate in the intermolecular interactions. ring). On the other hand, weaker CH/Cl linkages connect these
Replacement of Ph substituents with OPh ones in C1OPh disrupts 1D chains together thus forming (011) layers. Moreover the
the self-association of the tin adducts via CH/Cl hydrogen bonds. H/H interactions contribute to the stabilization of the supra-
Accordingly, the crystal structure is governed by CH/OR hydrogen molecular association.
˚
˚
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Table 1 Selected bond lengths (A˚) and angles (ꢀ) for crystalline compounds
Compounds
P–(C/N/O)R
P–(N/O)X
P]O
Sn–O
Sn–Cl
Sn–C
<O–Sn–Cl
<C–Sn–C
Ligand
6Ph
1.800(4)
1.800(4)
1.665(3)
1.489(3)
—
—
—
—
—
Complexes
C1OPh
1.5733(11)
1.5746(11)
1.5818(11)
1.4552(11)
1.4853(12)
1.475(3)
2.642(4)
2.4260(4)
2.4918(4)
2.5177(11)
2.4743(5)
2.5064(3)
2.1220(13)
2.1246(14)
2.1266(14)
2.1224(17)
2.1229(17)
2.1304(16)
2.117(4)
178.24(2)
179.05(3)
176.60(8)
179.48(4)
177.897(19)
120.89(5)
116.39(6)
114.53(5)
121.95(7)
118.95(7)
115.79(6)
115.67(16)
125.64(15)
117.54(15)
113.87(8)
120.45(8)
123.01(7)
120.06(4)
120.04(4)
118.75(4)
C2Ph
1.7926(16)
1.7953(17)
1.64(4) (P–N)
1.59(3) (P–O)
2.3922(12)
2.313(3)
C4NOPh
C5OPh
C6Ph
1.630(4) (P–N)
1.593(4) (P–O)
1.559(5)
1.594(2)
1.6530(8)
2.136(4)
2.137(4)
1.5745(17)
1.5855(15)
1.4599(12)
1.5022(8)
2.4725(12)
2.3531(7)
2.1215(19)
2.1268(19)
2.1287(18)
2.1243(10)
2.1295(10)
2.1436(10)
1.7956(10)
1.7973(10)
interactions in C5OPh have been omitted, however the overall
architecture of the crystal structure remained intact.
The more hindered nature of the para- and especially meta-
(NHCH2)2C6H4 spacers in C4PONH and C5OPh, respectively, don't
allow a close approach of neighbouring complexes necessary for
the formation of intermolecular CH/p and p–p interactions.
The NH/p and H/H connections in C4OPh is also due to a lesser
hindrance of para-spacer relative to that of meta-central part.
Non-covalent binding energies
Intermolecular binding energies, DE, were calculated, at the
M062X/LANL2DZ/6-311G* level, to characterize the strength of
these interactions compared to each other and to the coordi-
nation bonds in the crystal structures. DESn–O values, from
ꢁ26.19 to ꢁ37.57 kcal molꢁ1, represent a weak to medium-
strong Sn–O interaction for this class of ligands. As shown in
Table 2, the hydrogen binding energies are in agreement with
the strength of H-bonds (NH/Cl > CH/Cl). It should be noted
that in the case of C1OPh, given DE in Table 2, doesn't represent
the energy of the CH/O interaction individually but reects an
overall binding energy from a combination of CH/O and
several weak H/H interactions. Although CH/p (estimated
DE about 2–3 kcal molꢁ1), C/C and H/H interactions are
weak, their sum makes a signicant contribution to the crystal
packing of 6Ph, C6Ph, C2Ph and C1OPh. Besides, cooperative
effects between these weak interactions seem to play an
important role in the stability of crystalline structure. Supra-
molecular assembly of C4NOPh and C5OPh, including NH func-
tional groups are rstly driven by NH/Cl hydrogen bonds,
followed by CH/Cl linkages.
Fig. 2 (a) H-bonded chain in the crystal 6Ph along the c-axis. (b)
Fragment of the crystal packing along the b-axis.
Similar crystal packing pattern were observed for C5OPh
(Fig. 7). In this structure, the chlorine atoms, as bifurcated
acceptors, are involved in intermolecular NXH/Cl and CH/Cl
hydrogen bonds, leading to the formation of 2D layers which
are directed along the [011] plane. In other words, each layer
consists of alternative chains formed by successive NXH/Cl or
CH/Cl interactions. By changing the position of NXH groups
from para to meta and replacing An with OPh, NH/p
Fully optimized structures in the gas phase
Only ve structures are hardly sufficient to furnish a systematic
and comparative picture of the complexes. Crystallographic
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Table 2 Hydrogen bonding interactions for complexes C6Ph, C2Ph, C1OPh, C4NOPh and C5OPh (all distances in A˚ and angles in ꢀ
)
Compounds
DH/A
D/A
D–H
H/A
<C–H–Cl
DE (kcal molꢁ1
)
Symmetry codes
C6Ph
C2Ph
C1OPh
C4NOPh
C27–H27A/Cl1
C3–H3A/Cl1
C26–H26/O3
C17–H17A/Cl1
N1–H1N/Cl1
C24–H24/Cl1
N4–H400/Cl1
3.521(1)
3.742(2)
3.365(2)
3.774(5)
3.303(5)
3.715(3)
3.441(3)
0.950
0.950
0.931
0.950
0.880
0.930
0.870
2.8896
2.9408
2.710
2.860
2.730
2.865
2.710
124.98
142.8
128.1
162.5
124.0
152.5
1420
ꢁ5.72
ꢁ5.44
ꢁ10.07
ꢁ6.71
x,ꢁ1 + y,z
1/2 + x,3/2 ꢁ y,1/2 + z
x,1/2 ꢁ y,1/2 + z
x,ꢁy,ꢁ1/2 + z
ꢁ23.60 ꢁ 2DENH/p
ꢁ6.12
x,1 ꢁ y,ꢁ1/2 + z
x,1 ꢁ y,ꢁ1/2 + z
x,ꢁy,ꢁ1/2 + z
C5OPh
ꢁ8.16
Fig.
3 Packing diagram of C6Ph, formed by supramolecular
interactions.
Fig.
6 Representation of intermolecular interactions in C4NOPh,
resulting in 2D arrangements.
Fig. 4 Representation of CH/Cl interactions, creating 2D aggrega-
tions in C2Ph
.
Fig. 7 Packing diagram of C5OPh, formed by NXH/Cl and CH/Cl
hydrogen bonds.
data do neither provide a clear and true insight into tin–ligand
interactions as a function of phosphorus substituents, since the
geometry adopted in a crystal is not only the result of its
intrinsic properties but also of the external inuence of packing
effects. Therefore, in supplement, the geometries of all
compounds was fully optimized using DFT calculations at the
B3LYP level and subsequently, QTAIM and NBO analyses were
performed to obtain more information about bonding and
Fig. 5 Representation of CH/O interactions in C1OPh
.
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electronic aspects of the coordination compounds. The evalu- coordination bonds in the complexes containing Ph substitu-
ated geometrical parameters are presented in Table S3.† ents with the aliphatic spacers (C5Ph and C6Ph) indicate stronger
Sn–O interaction as a function of ligand substitution. Based Sn–O interactions compared to the other compounds possess-
on the QTAIM theory, the electron density (r), its Laplacian (V2r) ing OPh or An groups (E(2) ¼ 18.64–25.00 kcal molꢁ1). This is in
and electronic energy density (H(r)) at a bond critical point agreement with the order of the ligand Lewis basicities.
(BCP) give us information about the strength and characteristics
The negative charge on OP]O, q(OP]O), enhances from OPh
of the bond. Generally, a large value of r and V2r < 0 refers to a to Ph substitutions in the ligands, owing to the electron-
shared interaction or covalent bond, while a small r value and withdrawing nature of the phenoxy groups. Consistent with
V2r > 0 correspond to closed-shell interactions (e.g. ionic and this, hybridization of LP(OP]O) possesses a higher p character
hydrogen bonds and van der Waals interactions).20 However, a in the diphosphine dioxides (Table S5†). The results reveal a
clear distinction between closed-shell and covalent-type inter- higher electron availability and thus a higher basic potential of
actions is impossible without determining H(r). According to the diphosphine dioxides among the investigated ligands.
Rozas et al.,21 for strong interactions (V2r < 0 and H(r) < 0), Furthermore, a slightly higher electron availability was observed
indicate covalent character and medium-strength interactions for the ligands with an aliphatic spacer compared to the cor-
(V2r > 0 and H(r) < 0) partial covalent character, whereas weak responding ligands including aromatic central part. The trend
interactions (V2r > 0 and H(r) > 0) are mainly electrostatic. Thus, observed for the ligand basicity is also supported by QTAIM
the magnitude of H(r) at a BCP, instead of V2r, might be a more analysis.
reliable index for characterizing a weak interaction.
Coordination pattern. This section is intended to seek
The calculated average r, V2r and H(r) values at the BCP of reasons for the adopted structures in the tin(IV) adducts.
P]O, Sn–O and Sn–Cl bond paths are summarized in Table S4.† Bridging mode for the rigid bisphosphoryl ligands with the
Analysis of the obtained bond critical points for Sn–O interac- aromatic central part is predictable. For the ligands possessing
tions, suggests a closed-shell interaction and ionic character of a rather exible central moiety, meta- and para-diaminoxylene,
Sn–O in the title complexes. The r values at the Sn–O BCPs are the separation between the donor atoms is still too large to form
small in the range of 0.020–0.038 au and the corresponding V2r suitable chelates. In contrast, it would be expected that the
values are all positive, ranging from 0.077 to 0.151 au. For the exible aliphatic backbone in 6Ph allow the ligand to adopt a
complexes C2Ph, C5Ph and C6Ph, despite falling in a region of chelate arrangement. But bis(diphenylphosphino)piperazine
charge depletion with V2r > 0, the small negative values of H(r) dioxide complex C6Ph prefers again the binuclear pattern. Why
show that the interactions are principally electrostatic in nature do the bridging ligands enforce molecular binuclear structures
with a small amount of tin–ligand covalent interaction.
rather than polymeric architecture?
Based on NBO calculations, the size of stabilizing energies,
Binuclear arrangements instead of chelating or polymeric
E
(2), for the electronic delocalization LP(donor) to LP*(Sn) can systems may be attributed to the tendency of SnPh3Cl to
be used to characterize the strength of the donor–acceptor produce a trigonalbipyramidal stereochemistry. In other word,
coordination interactions. From the results in Table S5,† the the steric demands of SnPh3Cl, due to the presence of three
higher stabilizing energies of 32.38 and 32.98 kcal molꢁ1 for the bulky phenyl groups on tin, lead to the formation of ve-
Table 3 Spectroscopic data of compounds
IR (cmꢁ1
n(N–H)
Ligand
)
NMR (ppm)
d(31P)
d(119Sn)
n(P]O) exp./cal.
n(P–N/O)
Compound
Complex
Ligand
Complex
Ligand
Complex
Ligand
Complex
Complex
C1OPh
C2OPh
—
3155
—
3176
1307/1289
1289/1284
1288/1268
1275/1269
960
962
963
967
ꢁ17.57
ꢁ6.85
ꢁ17.21
16.20
28.09
ꢁ6.54
ꢁ1.37
4.14
ꢁ17.60
ꢁ7.29
ꢁ17.26
16.33
28.10
ꢁ7.41
ꢁ1.51
3.99
ꢁ46.2
ꢁ48.2
C2Ph
3248
3369
1205/1231
1177/1150
926
938
ꢁ50.8
C3OPh
C4OPh
C4NOPh
3175
3218
3390
3202
3185
3247
3351
3362
3277
3343
3305
3366
3289
3341
—
1258/1279
1251/1284
1211/1266
1251/1262
1238/1233
1197/1212
946
936
930
937
953
946
ꢁ49.2
ꢁ48.0
ꢁ44.2
a
C5OPh
1240/1286
1208/1268
1235/1234
1201/1201
926
928
951
940
ꢁ1.42
ꢁ1.49
—
C5NOPh
3387
3203
3134
—
4.37
4.22
23.82
32.08
3.94
3.71
24.55
31.80
ꢁ47.7
C5Ph
C6Ph
1193/1211
1179/1207
1132/1149
1127/1160
1065
952
996
963
ꢁ80.8
ꢁ180.7
a
Low solubility.
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coordinate complexes in most cases.11,22,23 Therefore, for having Similarly phosphorus chemical shis of complexes are also very
two coordinative sites on triphenyltin the Clꢁ ion would have to close to the values of the related ligands. These results are not
be dissociated. It seems Sn–Cl bonding is too strong to be informative enough to be evidence of the adducts in solution.
replaced by Sn–O coordination.
Finally, 119Sn resonance for C1OPh–C5Ph compared to reported
Corroborating the solid-state structures, the QTAIM value for free SnPh3Cl (ꢁ44.7 in CDCl3)2 reveal that these
parameters at the Sn–Cl critical points are indicative of a larger complexes are partially or almost completely dissociated in
electrostatic contribution for the Sn–Cl bonds than Sn–O solution.
interactions. Furthermore, on the basis of the NBO analysis,
In fact, we have here an equilibrium between the bis-
the stabilizing energies, E(2), of 141.00–161.08 kcal molꢁ1 for a triphenyltin adduct and 2Ph3SnCl + ligand that, at ambient
LP(Cl) / LP*(Sn) electron-density transfer in comparison with temperature, is fast on the NMR time scale. This result is in
a LP(Cl) / LP*(Sn) delocalization energy (E(2) ¼ 18.64–32.98 accordance with other triphenyltin adducts which are kineti-
kcal molꢁ1) conrm that the chloride ion interact more cally labile in the solution phase.11,14a,15b,24 Although, the 119Sn
strongly with tin(IV) than the neutral phosphoryl group (Tables resonance for C5Ph shis to ꢁ80.8 ppm, such chemical shi is
S4 and S5†).
not still in the range for the ve-coordinated tin compounds.25
The upeld shi may be due to more population of the tin(IV)
adduct compared to the free SnPh3Cl in the equilibrium,
agreeing with the stronger Sn–ligand interaction in this
Spectroscopic characterization
All compounds were characterized by IR and multinuclear NMR compound than others.
spectroscopy. As shown in Table 3, the experimental P]O
Since the complex C6Ph is not soluble in chloroform, the
stretching frequencies decreases in line with polarizability and NMR spectra of this compound and its ligand (for comparison)
therefore basicity of the ligands, from 1OPh with OPh substit- were recorded in methanol. The d(119Sn) appeared at ꢁ180.7
uents and aromatic spacer (1306 cmꢁ1) to 5Ph and 6Ph ppm for C6Ph falling in the range of ve coordinated tin(IV)
including Ph substituents and aliphatic spacers (1192 and 1193 centers. According to the value of ꢁ178.6 ppm for the free
cmꢁ1). Similar trend was also obtained in the n(P]O) vibra- SnPh3Cl in methanol, such chemical shi attributed to forma-
tional modes for the fully optimized ligands in the gas phase. tion of species Ph3Sn(OCD3) in solution.
However, in most cases, the calculated bands compared to the
solid state ones appear in higher frequencies which is partly due
to the absence of hydrogen bonds in the gas phase calcula-
Conclusions
tions.9 Besides, a signicant decreasing of the P]O stretching Triphenyltin(IV) adducts with the family of diphosphoryl
frequencies is observed by ligation of the diphosphoryl ligands. ligands, RR0P(O)–X–P(O)RR0, are presented. X-Ray crystallog-
This is due to the electron donation to Sn(IV) and consequently raphy conrms the binuclear structures for the tin(IV) adducts
increasing the P]O distance. IR spectra reveal that the low- with two trans SnPh3Cl moieties linked via the bridging ligands.
frequency shis are higher in the complexes C5Ph and C6Ph The coordination binding energies represent
a weak to
(including Ph groups as phosphorous substituents with the medium-strong Sn–O interaction for this class of ligands. The
aliphatic spacer), conrming that the Sn–O interaction in these analysis of the crystal packing reveals CH/Cl interactions to be
compounds is stronger than that in others. Moreover, the P–N the main factor governing the supramolecular assembly of the
stretching bands in the most complexes were found greater complexes C2Ph and C6Ph. Replacement of Ph substituents with
than that observed in the ligands, in agreement with the OPh in C1OPh, causes the formation of CH/OR hydrogen
shortening of the P–N bonds in the complexes. A similar shi in bonded networks. Self-association of C4NOPh and C5OPh
,
n(P–N) values has been obtained for the optimized geometries including NXH functional groups, are rstly driven by NH/Cl
(Table S6†). Other prominent bands at 3135–3387 cmꢁ1 are hydrogen bonds, followed by weaker CH/Cl linkages. Notably,
assigned to N–H vibrational modes that shi toward higher the higher hindrance of diaminoxylene spacers in these
frequencies in the coordinated ligands. Whereas the N–H bond complexes does not allow the close approach of neighbouring
participates in the hydrogen bonding, the positive shi of units necessary for the formation of intermolecular CH/p and
n(N–H) may be attributed to the weakening of the hydrogen p–p interactions. Different R-substituents and X-spacers do not
bonds from NH/OP]O in the free ligands to NH/Cl in their only affect the crystal packing, but also the donation ability of
complexes. Since the hydrogen bonding is absent in the opti- the ligands to tin. The result from QTAIM and NBO analyses on
mized single molecules, the calculated n(N–H) values (from the optimized molecular structures demonstrate a higher elec-
3591 to 3610 cmꢁ1 for all compounds) are larger in magnitude tron polarizability and thus a higher basic potential for the
than those of hydrogen bonded molecules in the solid phase.
diphosphine dioxides with the aliphatic central part (5Ph and
The 1H NMR spectral data obtained for ligands are indicative 6Ph) among the investigated ligands. This result is further
of the expected structure for these molecules. As well, the supported by spectroscopic evidence. Tin–ligand interactions
integrated proton NMR spectrum of complexes are consistent are principally electrostatic in nature with a small amount of
with the formula of binuclear adducts, which exhibit covalent overlap in the tin adducts with diphosphine dioxides.
the expected proton signals for a bridging ligands and two tri- Last but not least is the similarity of the molecular structures of
phenyltin(IV). Besides, no remarkable change is occurred in all complexes owing to the steric demands of SnPh3Cl, despite
chemical shis and coupling constants by coordination to tin. the structural diversity of the ligands.
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(nNH), 1251s (nP]O), 1187s, 936s (nP–N). H NMR (CDCl3, ppm):
Experimental
Materials and methods
3
d ¼ 3.45 (br, 2H, 2NH), 4.23 (d, 4H, JHH 9.9 Hz, 2CH2),7.13
3
(s, 4H, C6H4), 7.17 (t, 4H, JHH 7.2 Hz, 4p-OPh), 7.24 (d, 8H,
3JHH 7.7 Hz, 4o-OPh), 7.32 (t, 8H, 3JHH 7.8 Hz, 4m-OPh). 31P NMR
(CDCl3, ppm): d ¼ ꢁ1.37.
All chemicals and solvents are commercially available and were
used as received without further purication.
1H, 31P and 119Sn NMR spectra were recorded on a Bruker
Advance 300 spectrometer at 300.13, 121.50 and 111.86 MHz,
respectively. 1H chemical shis were determined relative to
Si(CH3)4. 31P and 119Sn chemical shis were measured relative
to 85% H3PO4 and Sn(CH3)4 as external standard respectively.
Infrared (IR) spectra were recorded on KBr disk using a Shi-
madzu model IR-60 spectrometer. Elemental analysis was per-
formed using a Heraeus CHN-O-RAPID apparatus.
1,4-[(C6H5O)(C6H5NH)P(O)NHCH2]2C6H4 (4NOPh). Mp:
180 ꢀC. Anal. calc. for C32H32N4O4P2: C, 64.21; H, 5.39; N, 9.36;
found: C, 64.29; H, 5.65; N, 9.05%. Selected IR data
(KBr, cmꢁ1): 3390m, 3202m (nNH), 1211s (nP]O), 930s (nP–N).
1H NMR (CDCl3, ppm): d ¼ 3.45 (dt, 2H, 2JPH 11.2 Hz, 3JHH 6.5
Hz, NHX), 4.05 (m, 4H, 2CH2), 5.94 (d, 2H, 2JPH 8.5 Hz, NHAn),
7.05–7.27 (m, 24H, C6H4 + 2OPh + 2An). 31P NMR (CDCl3,
ppm): d ¼ 4.14.
1,3-[(C6H5O)2P(O)NHCH2]2C6H4 (5OPh). Mp: 94–102 ꢀC.
Anal. calc. for C32H30N2O6P2: C, 64.00; H, 5.04; N, 4.66; found: C,
64.29; H, 4.95; N, 4.55%. Selected IR data (KBr, cmꢁ1): 3185m
General procedure for the preparation of ligands
(C6H5O)(C6H5NH)P(O)Cl was prepared by the reaction of aniline (nNH), 1240s (nP]O), 1191s, 926s (nP–N). 1HNMR (CDCl3, ppm): d
with (C6H5O)P(O)Cl2 in 2 : 1 molar ratio. The amine was added ¼ 3.26 (dt, 2H, 2JPH 12.5 Hz, 3JHH 6.9 Hz, 2NH), 4.18 (dd, 4H, 3JPH
dropwise to a CH3CN solution (20 ml) of (C6H5O) P(O)Cl2 at 9.9 Hz, 3JHH 6.9 Hz, 2CH2), 6.97–7.35 (m, 24H, C6H4 + 4OPh). 31
0 ꢀC. Aer 4 h stirring, the solvent was removed in vacuum and NMR (CDCl3, ppm): d ¼ 1.42.
P
the resulting was washed with distilled water and dried.
1,3-[(C6H5O)(C6H5NH)P(O)NHCH2]2C6H4 (5NOPh). Mp:
The ligands were synthesized from the reaction of 2 mmol 150 ꢀC. Anal. calc. for C32H32N4O4P2: C, 64.21; H, 5.39; N, 9.36;
RR0P(O)Cl with 1 mmol of the corresponding diamine, amino- found: C, 64.18; H, 5.70; N, 9.15%. Selected IR data (KBr, cmꢁ1):
alcohol or dialcohol in presence of Et3N as HCl scavenger in 3387s, 3203m (nNH), 1208s (nP]O), 928m (nP–N). 1HNMR (CDCl3,
3
CH2Cl2 or CH3CN at room temperature. Aer stirring for 24 h, ppm): d ¼ 3.08 (m, 2H, 2NHX), 4.03 (dd, 4H, JPH 11.2 Hz, 3JHH
the solvent was evaporated and the residue was washed with 6.9 Hz, 2CH2), 6.00 (d, 1H, 2JPH 8.8 Hz, NHAn), 6.16 (d, 1H, 3JPH
distilled water and dried. Physical and spectroscopic data of the 8.8 Hz, NHAn), 6.88–7.40 (m, 24H, C6H4 + 2Oph + 2An). 31P NMR
ligands are presented below:
(CDCl3, ppm): d ¼ 4.22, 4.37.
1,4-[(C6H5O)2P(O)O]2C6H4 (1OPh).26. Mp: 105 ꢀC. Anal. calc.
1,3-[(C6H5)2P(O)NHCH2]2C6H4 (5Ph). Mp: 162–165 C. Anal.
ꢀ
for C30H24O8P2: C, 62.72; H, 4.21; found: C, 62.90; H, 4.35%. calc. for C32H30N2O2P2: C, 71.63; H, 5.64; N, 5.22; found: C,
Selected IR data (KBr, cmꢁ1): 1307m (nP]O), 1168s, 960s (nP–O). 71.49; H, 6.12; N, 5.34%. Selected IR data (KBr, cmꢁ1): 3134m
1H NMR (CDCl3, ppm): d ¼ 7.22–7.26 (m, 16H, C6H4 + 4OPh), (nNH), 1193s (nP]O), 1065s (nP–N), 904w. 1HNMR (CDCl3, ppm): d
7.33–7.39 (m, 8H, C6H4 + 4OPh). 31P NMR (CDCl3, ppm): d ¼ ¼ 3.19 (ps-q, 2H, 2JPH 6.6 Hz, 2NHX), 4.12 (ps-t, 4H, 2JPH 7.6 Hz,
ꢁ17.57.
2CH2), 7.26–7.29 (m, 3H, C6H4), 7.35 (s, 1H, C6H4), 7.40–7.52 (m,
1,4-[(C6H5O)2P(O)NHC6H4OP(O)(OC6H5)2] (2OPh). Mp: 12H, 4Ph), 7.94 (m, 8H, 4Ph). 31P NMR (CDCl3, ppm): d ¼ 23.82.
95 C. Anal. calc. for C30H25NO7P2: C, 62.83; H, 4.39; N, 2.44;
1,4-[(C6H5)2P(O)N]2C4H8 (6Ph).28. Mp: 235 ꢀC. Anal. calc. for
ꢀ
found: C, 62.50; H, 4.17; N, 2.39%. Selected IR data (KBr, cmꢁ1):
C
28H28N2O2P2: C, 69.13; H, 5.80; N, 5.76; found: C, 69.09; H,
3155w (nNH), 1289m (nP]O), 1186s, 962s (nP–N). 1H NMR 6.02; N, 5.54%. Selected IR data (KBr, cmꢁ1): 3501m, 3431m
(CDCl3, ppm): d ¼ 7.04–7.39 (m, 24H, C6H4 + 4OPh). 31P NMR (nH2O), 1179s (nP]O), 952s (nP–N). 1HNMR (MeOD, ppm): d ¼ 3.08
(CDCl3, ppm): d ¼ ꢁ6.85 (PP–N), ꢁ17.21 (PP–O).
(m, 8H, C4H8), 7.48–7.57 (m, 12H, 4Ph), 7.80–7.88 (m, 8H, 4Ph).
1,4-[(C6H5)2P(O)NHC6H4OP(O)(C6H5)2] (2Ph). Mp: 264 ꢀC. 31P NMR (MeOD, ppm): d ¼ 32.08.
Anal. calc. for C30H25NO3P2: C, 70.72; H, 4.95; N, 2.75; found: C,
70.52; H, 5.23; N, 2.80%. Selected IR data (KBr, cmꢁ1): 3248w
(nNH), 1205s (nP]O), 938s (nP–N). 1H NMR (CDCl3, ppm): d ¼ 5.35
General procedure for the preparation of complexes
(d, 1H, 2JPH 9.5 Hz, NH), 6.84 (d, 2H, 3JHH 10.8 Hz, C6H4), 6.95 (d, The complexes were prepared by using the following similar
3
2H, JHH 10.2 Hz, C6H4), 7.42–7.54 (m, 12H, 4Ph), 7.79 (t, 4H, procedure: methanol–chloroform solutions of 2 eq. SnPh3Cl
3JHH 7.7 Hz, 4m-Ph), 7.84 (t, 4H, JHH 7.0 Hz, 4m-Ph). 31P NMR and 1 eq. the corresponding ligand were mixed. Crystals suit-
3
(CDCl3, ppm): d ¼ 28.09 (PP–O), 16.20 (PP–N).
able for X-ray diffraction were obtained from slow evaporation
1,4-[(C6H5O)2P(O)NH]2C6H4 (3OPh).27. Mp: 147 ꢀC. Anal. of the solution at room temperature. Physical and spectroscopic
calc. for C30H26N2O6P2: C, 62.94; H, 4.58; N, 4.89; found: C, data of the complexes are given below:
62.62; H, 4.65; N, 4.80%. Selected IR data (KBr, cmꢁ1): 3175m
m-{1,4-[(PhO)2P(O)O]2C6H4}[SnPh3Cl]2 (C1OPh). Mp: 115 ꢀC.
(nNH), 1258s (nP$O), 1196s, 988s, 946s (nP–N). 1H NMR (CDCl3, Anal. calc. for C66H54Cl2O8P2Sn2: C, 58.92; H, 4.05; found: C,
ppm): d ¼ 5.2 (d, 2H, 3JHH 8.5 Hz, 2NH), 7.09 (s, 4H, C6H4), 7.19– 59.19; H, 4.25%. Selected IR data (KBr, cmꢁ1): 1288m (nP]O),
7.27 (m, 20H, 4Oph). 31P NMR (CDCl3, ppm): d ¼ ꢁ6.54.
1162s, 963s (nP–O). 1H NMR (CDCl3, ppm): d ¼ 7.21–7.27 (m,
1,4-[(C6H5O)2P(O)NHCH2]2C6H4 (4OPh). Mp: 98 ꢀC. Anal. 16H, C6H4 + 4OPh), 7.34–7.39 (m, 8H, C6H4 + 4OPh), 7.47–7.52
calc. for C32H30N2O6P2: C, 64.00; H, 5.04; N, 4.66; found: C, (m, 18H, Ph3Sn), 7.67–7.70 (m, 12H, o-Ph3Sn). 31P NMR (CDCl3,
64.32; H, 4.75; N, 4.45%. Selected IR data (KBr, cmꢁ1): 3218w ppm): d ¼ ꢁ17.60. 119Sn NMR (CDCl3, ppm): d ¼ ꢁ46.2.
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10.3 Hz, 3JHH 6.8 Hz, 2CH2), 5.52 (d, 1H, 2JPH 7.9 Hz, NHAn), 5.80
m-{1,4-[(PhO)2P(O)NHC6H4OP(O)(OPh)2]}[SnPh3Cl]2 (C2OPh).
Mp: 72 ꢀC. Anal. calc. for C66H55Cl2NO7P2Sn2: C, 58.96; H, 4.12;
N, 1.04; found: C, 59.20; H, 4.50; N, 1.35%. Selected IR data
3
(d, 1H, JPH 8.9 Hz, NHAn), 6.94–7.30 (m, 24H, C6H4 + 2Oph +
2An), 7.46–7.49 (m, 18H, 2Ph3Sn), 7.66–7.70 (12H, 2o-Ph3Sn). 31
P
NMR (CDCl3, ppm): d ¼ 3.71, 3.94. 119Sn NMR (CDCl3, ppm):
d ¼ ꢁ47.7.
1
(KBr, cmꢁ1): 3176w (nNH), 1275m (nP]O), 1185s, 967s (nP–N). H
NMR (CDCl3, ppm): d ¼ 6.48 (d, 1H, 2JPH 10.0 Hz, NH), 7.06–7.39
(m, 24H, C6H4 + 4OPh), 7.47–7.49 (m, 18H, 2Ph3Sn), 7.67–7.71
(m, 12H, 2o-Ph3Sn). 31P NMR (CDCl3, ppm): d ¼ ꢁ7.29 (PP–NH),
ꢁ17.26 (PP–O). 119Sn NMR (CDCl3, ppm): d ¼ ꢁ48.2.
m-{1,3-[(Ph)2P(O)NHCH2]2C6H4}[SnPh3Cl]2 (C5Ph). Mp: 118–
120 ꢀC. Anal. calc. for C68H60Cl2N2O2P2Sn2: C, 62.47; H, 4.63; N,
2.14; found: C, 61.99; H, 4.83; N, 2.35%. Selected IR data (KBr,
cmꢁ1): 3341m (nNH), 1132s (nP]O), 996s (nP–N). 1H NMR (CDCl3,
ppm): d ¼ 3.11 (ps-q, 2H, 3JPH 5.8 Hz, NH), 3.96 (ps-t, 4H, 3JPH 7.6
Hz, CH2), 7.19–7.27 (m, 4H, C6H4), 7.41–7.49 (m, 30H, 4Ph +
Ph3Sn), 7.75–7.87 (m, 20H, 4Ph + Ph3Sn). 31P NMR (CDCl3,
ppm): d ¼ 24.55. 119Sn NMR (CDCl3, ppm): d ¼ ꢁ80.8.
m-{1,4-[(Ph)2P(O)N]2C4H8}[SnPh3Cl]2 (C6Ph). Mp: 243 ꢀC.
Anal. calc. for C64H58Cl2N2O2P2Sn2: C, 61.13; H, 4.65; N, 2.23;
found: C, 61.40; H, 4.95; N, 2.32%. Selected IR data (KBr, cmꢁ1):
1127s (nP]O), 963m (nP–N). 1H NMR (MeOD, ppm): d ¼ 3.10 (m,
8H, C4H8), 7.50–7.57 (m, 12H, 4Ph), 7.80–7.91 (m, 8H, 4Ph),
7.44–7.51 (m, 18H, Ph3Sn), 7.67–7.70 (m, 12H, o-Ph3Sn). 31P
NMR (MeOD, ppm): d ¼ 31.80. 119Sn NMR (MeOD, ppm):
d ¼ ꢁ180.7.
m-{1,4-[(Ph)2P(O)NHC6H4OP(O)(Ph)2]}[SnPh3Cl]2 (C2Ph). Mp:
168 ꢀC. Anal. calc. for C66H55Cl2NO3P2Sn2: C, 61.91; H, 4.33; N,
1.09; found: C, 61.30; H, 4.85; N, 1.25%. Selected IR data (KBr,
1
cmꢁ1): 3369w (nNH), 1177s (nP]O), 938s (nP–N). H NMR (CDCl3,
ppm): d ¼ 5.30 (d, 1H, 2JPH 9.1 Hz, NH), 6.82 (d, 2H, 3JHH 8.9 Hz,
C6H4), 6.93 (d, 2H, 3JHH 8.8 Hz, C6H4), 7.40–7.52 (m, 31H, 4Ph +
Ph3Sn), 7.67–7.70 (m, 10H, 4Ph + Ph3Sn), 7.77–7.84 (m, 9H, 4Ph
+ Ph3Sn). 31P NMR (CDCl3, ppm): d ¼ 28.10 (PP–O), 16.33 (PP–NH).
119Sn NMR (CDCl3, ppm): d ¼ ꢁ50.8.
m-{1,4-[(PhO)2P(O)NH]2C6H4}[SnPh3Cl]2 (C3OPh). Mp: 98 ꢀC.
Anal. calc. for C66H56Cl2N2O6P2Sn2: C, 59.01; H, 4.20; N, 2.09;
found: C, 59.19; H, 4.76; N, 1.85%. Selected IR data (KBr, cmꢁ1):
1
3247m (nNH), 1251s (nP]O), 1190s, 948s (nP–N), 1015w. H NMR
3
(CDCl3, ppm): d ¼ 5.4 (d, 2H, JHH 8.8 Hz, 2NH), 7.10 (s, 4H,
C6H4), 7.19–7.32 (m, 20H, 4Oph), 7.46–7.49 (m, 18H, 2Ph3Sn),
7.66–7.69 (12H, 2o-Ph3Sn). 31P NMR (CDCl3, ppm): d ¼ ꢁ7.41.
119Sn NMR (CDCl3, ppm): d ¼ ꢁ49.2.
Crystal structure determination
X-ray crystallography for 6Ph, C2Ph, C4NOPh and C6Ph. X-ray
intensities of ligand 6Ph and complexes C2Ph, C4NOPh and C6Ph
were collected on a Bruker SMART APEXII CCD diffractometer
m-{1,4-[(PhO)2P(O)NHCH2]2C6H4}[SnPh3Cl]2 (C4OPh). Mp:
98 ꢀC. Anal. calc. for C68H60Cl2N2O6P2Sn2: C, 59.55; H, 4.41; N,
2.04; found: C, 59.01; H, 4.80; N, 1.90%. Selected IR data (KBr,
˚
with graphite-monochromatized MoKa radiation (l ¼ 0.71073 A).
1
cmꢁ1): 3351w (nNH), 1238s (nP]O), 1188s, 922s, 953s (nP–N). H
Cell renement and data reduction were performed with the help
of the programs APEX2 (ref. 29) and SAINT.29 The structures were
solved and rened with SHELXTL (5.1)30 by full-matrix least-
squares on F2. All non-hydrogen atoms were rened anisotropi-
cally. Ligand 6Ph was already solved at room temperature,31 but
lacked an absorption correction. Our determination (T ¼ 100 K,
with absorption correction) furnishes more details; so we report
it anyway. C4NOPh is a superposition structure. Indeed, the
Ph3ClSn moieties are related by an inversion, but the ligand
which – according to the synthesis – is achiral may adopt one of
two orientations in different cells. No SRO is expected for this
NMR (CDCl3, ppm): d ¼ 3.33 (m, 2H, 2NH), 4.24 (dd, 4H, 2JPH 9.7
3
3
Hz, JHH 6.9 Hz, 2CH2), 7.12 (s, 4H, C6H4), 7.17 (t, 4H, JHH 7.2
Hz, p-OPh), 7.24 (d, 8H, 3JHH 7.7 Hz, o-OPh), 7.32 (t, 8H, 3JHH 7.8
Hz, m-OPh). 31P NMR (CDCl3, ppm): d ¼ ꢁ1.51. 119Sn NMR
(CDCl3, ppm): d ¼ ꢁ48.0.
m-{1,4-[(PhO)(PhNH)P(O)NHCH2]2C6H4}[SnPh3Cl]2 (C4NOPh).
Mp: 152 ꢀC. Anal. calc. for C68H62Cl2N4O4P2Sn2: C, 59.64; H,
4.56; N, 4.09; found: C, 59.07; H, 4.62; N, 3.90%. Selected IR data
(KBr, cmꢁ1): 3362m, 3277m (nNH), 1197s (nP]O), 946s (nP–N). 1H
2
3
NMR (CDCl3, ppm): d ¼ 3.37 (dt, 2H, JPH 18 Hz, JHH 10.8 Hz,
NHX), 4.05 (m, 4H, 2CH2), 5.84 (d, 2H, 8.5 Hz, NHAn), 6.95–7.28
(m, 24H, C6H4 + 2OPh + 2An), 7.44–7.51 (m, 18H, Ph3Sn), 7.67–
7.73 (m, 12H, o-Ph3Sn). 31P NMR (CDCl3, ppm): d ¼ 3.99. 119Sn
NMR (CDCl3, ppm): d ¼ ꢁ44.2.
ꢀ
phenomenon. Therefore, the space group P2c is a very good
description even with only one ligand. Indeed, all the atoms, but
the O and N atoms of the OPh and NPh moieties overlap so
closely that a desymmetrization was unstable. Furthermore, the
U
jk tensors are big enough to encompass the positions of both,
m-{1,3-[(PhO)2P(O)NHCH2]2C6H4}[SnPh3Cl]2 (C5OPh). Mp:
96 ꢀC. Anal. calc. for C68H60Cl2N2O6P2Sn2: C, 59.55; H, 4.41; N,
2.04; found: C, 59.70; H, 4.52; N, 1.92%. Selected IR data (KBr,
cmꢁ1): 3343w, 3305w (nNH), 1235s (nP]O), 1186s, 951s (nP–N). 1H
NMR (CDCl3, ppm): d ¼ 3.17 (dt, 2H, 2JPH 12.3 Hz, 3JHH 7.1 Hz,
the O and N atoms, which also explains the borderline P–O and
P–N distances. Finally, this also means that the analysis of the
interactions is still valid, except that in certain cells some
interactions are active and others in different cells.
X-ray crystallography for C1OPh and C5OPh. Bragg-intensities
of C1OPh and C5OPh were collected on a Stoe IPDS II diffrac-
3
3
2NH), 4.18 (dd, 4H, JPH 9.8 Hz, JHH 6.9 Hz, 2CH2), 7.11–7.36
(m, 24H, C6H4 + 4OPh), 7.44–7.51 (m, 18H, Ph3Sn), 7.67–7.70
(m, 12H, o-Ph3Sn). 31P NMR (CDCl3, ppm): d ¼ ꢁ1.49.
˚
tometer with graphite-monochromatized MoKa (l ¼ 0.71073 A)
radiation. Cell renement, data reduction and a numerical
absorption correction were performed with the help of the
programs X-AREA (1.62)31 and XRED32 (1.31).32 The structure of
C3OPh was solved with direct methods using the program SIR
2004 (ref. 33) and that of C5OPh with Patterson methods using
the program DIRDIF-2008.34 The structure renement on F2 was
m-{1,3-[(PhO)(PhNH)P(O)NHCH2]2C6H4}[SnPh3Cl]2 (C5NOPh).
Mp: 142–146 ꢀC. Anal. calc. for C68H62Cl2N4O4P2Sn2: C, 59.64; H,
4.56; N, 4.09; found: C, 59.00; H, 4.60; N, 4.25%. Selected IR data
(KBr, cmꢁ1): 3366m, 3289m (nNH), 1201s (nP]O), 940m (nP–N). 1H
3
NMR (CDCl3, ppm): d ¼ 3.28 (m, 2H, 2NHX), 4.07 (dd, 4H, JPH
17490 | RSC Adv., 2015, 5, 17482–17492
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carried out with the program SHELXL-97.35 All non-hydrogen
atoms were rened anisotropically. The crystallographic and
renement data are summarized in Table S1† for all
compounds and hydrogen bonding data for the ligand 6Ph
given in Table S2.†
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311G*, but LanL2DZ38 was used for Sn atom. Then harmonic
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17492 | RSC Adv., 2015, 5, 17482–17492
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