The novel copper(I) π,σ-complexes with 1-(aryl)-5-(allylthio)-1H-tetrazoles: Synthesis, structure characterization, DFT-calculation and third-order nonlinear optics

Article abstract of DOI:10.1080/00958972.2019.1580699

The present work is directed toward preparation, structure and optical property characterization of tetrazole-containing Cu(I) compounds. By means of the alternating-current electrochemical technique copper(I) π,σ-compounds with 1-(4-methylphenyl)- (Matht), 1-(3-chloro-4-methylphenyl)- (Chmatht) and 1-[2-(trifluoromethyl)phenyl]- (Tfmatht) 5-(allylthio)-1H-tetrazoles were obtained in a single crystal form and structurally characterized by X-ray diffraction and Raman spectroscopy. Matht and Chmatht ligands, being attached to the Cu(I) through S-allylic C = C-bond and two tetrazole N-atoms, form stable centrosymmetric dimers [Cu₂(Matht)₂(H₂O)₂](BF₄)₂ and [Cu₂(Chmatht)₂(СlO₄)₂]. The presence of an electron acceptor trifluoromethyl group promotes formation of the monomeric [Cu(Tfmatht)₂]BF₄ and [Cu(Tfmatht)(NH₂SO₃)(MeOH)] compounds. The compounds were investigated by means of Raman spectroscopy, third-order nonlinear optics and DFT calculations.

Full text of DOI:10.1080/00958972.2019.1580699

Journal of Coordination Chemistry
ISSN: 0095-8972 (Print) 1029-0389 (Online) Journal homepage: https://www.tandfonline.com/loi/gcoo20
The novel copper(I) π,σ-complexes with 1-(aryl)-5-
(allylthio)-1H-tetrazoles: Synthesis, structure
characterization, DFT-calculation and third-order
nonlinear optics
Yurii Slyvka, Evgeny Goreshnik, Gleb Veryasov, Dmitry Morozov, Andrii A.
Fedorchuk, Nazariy Pokhodylo, Iwan Kityk & Marian Mys’kiv
To cite this article: Yurii Slyvka, Evgeny Goreshnik, Gleb Veryasov, Dmitry Morozov, Andrii
A. Fedorchuk, Nazariy Pokhodylo, Iwan Kityk & Marian Mys’kiv (2019): The novel copper(I)
π,σ-complexes with 1-(aryl)-5-(allylthio)-1H-tetrazoles: Synthesis, structure characterization,
DFT-calculation and third-order nonlinear optics, Journal of Coordination Chemistry, DOI:
10.1080/00958972.2019.1580699
To link to this article: https://doi.org/10.1080/00958972.2019.1580699
View supplementary material
Accepted author version posted online: 12
Feb 2019.
Submit your article to this journal
Article views: 5
View Crossmark data
Full Terms & Conditions of access and use can be found at
https://www.tandfonline.com/action/journalInformation?journalCode=gcoo20

The novel copper(I) π,σ-complexes with 1-(aryl)-5-(allylthio)-1H-tetrazoles:
Synthesis, structure characterization, DFT-calculation and third-order
nonlinear optics
YURII SLYVKA*†, EVGENY GORESHNIK‡, GLEB VERYASOV ‡§, DMITRY MOROZOV¶,
ANDRII A. FEDORCHUK†, NAZARIY POKHODYLO†, IWAN KITYKǁ and MARIAN MYS’KIV†
†Department of Chemistry, Ivan Franko National University of Lviv, Lviv, Ukraine
‡Department of Inorganic Chemistry and Technology, Jožef Stefan Institute, Ljubljana, Slovenia
§Institute for Regenerative Medicine, Sechenov University, Moscow, Russia
¶Department of Chemistry, Nanoscience Center, Univeristy of Jyväskylä, Jyväskylä, Finland
ǁInstitute of Optoelectronics and Measuring Systems, Faculty of Electrical Engineering, Czestochowa University of
Technology, Czestochowa, Poland
The present work is directed towards preparation, structure and optical property characterization
of tetrazole-containing Cu(I) compounds. By means of the alternating-current electrochemical
technique copper(I) π,σ-compounds with 1-(4-methylphenyl)- (Matht), 1-(3-chloro-4-
methylphenyl)- (Chmatht) and 1-[2-(trifluoromethyl)phenyl]- (Tfmatht) 5-(allylthio)-1H-
tetrazoles were obtained in a single crystal form and structurally characterized by X-ray
diffraction and Raman spectroscopy. Matht and Chmatht ligands, being attached to the Cu(I)
through S-allylic C=C-bond and two tetrazole N-atoms, form stable centrosymmetric dimers
[Cu2(Matht)2(H2O)2](BF4)2 and [Cu2(Chmatht)2(СlO4)2]. The presence of an electron acceptor
trifluoromethyl group promotes formation of the monomeric [Cu(Tfmatht)2]BF4 and
[Cu(Tfmatht)(NH2SO3)(MeOH)] compounds. The compounds were investigated by means of
Raman spectroscopy, third-order nonlinear optics and DFT calculations.
Keywords: Copper(I); Tetrazole; Crystal structure; DFT Calculation; Nonlinear optics
1. Introduction
The olefin copper(I) π-complexes are known to be an important class of coordination compounds
possessing a versatile applicability in chemistry and biology as well as in other areas of science;
they are useful as catalysts in organic syntheses, for their fluorescent activity, for their unique
role in crystal structure engineering and many other useful properties [1-7]. Formation of the
Cu(I)-(C=C) bond specifically reflects on the other interactions of copper(I) with σ-donor ligands
*Corresponding author. Email: yurii.slyvka@lnu.edu.ua
1

and strongly depends on the anion type as well as on the heteroatomic organic molecule
structure, its basicity, number of heteroatoms, etc. [2].
Copper ions may participate in a broad spectrum of intracellular processes under normal
and pathologic conditions [8]. For instance, Cu(I) complexes were used for in vitro tests as
potential anticancer drugs and have been found to be effective against A549 adenocarcinoma
cells that are resistant to the widely used anticancer drug, cisplatin [9]. Moreover, cancer
progression is accompanied by increased ceruloplasmin and copper levels in various tissues, and
the elevated copper levels and increased oxidative stress in cancer cells provide for a prospect of
selective cancer treatment [10, 11]. Taking into account that copper(I) complexes have also a
couple of potential applications in advanced laser operated materials [12], the exploration of their
nonlinear optical (NLO) features may be useful for the monitoring and clarification of the
mentioned biochemical mechanisms.
As it was shown recently, allyl derivatives of heterocyclic compounds, which unite rigid
heterocyclic cores and conformation-flexible allyl group, are suitable for the preparation of
π-compounds with unknown (or less-stable) in a free state copper(I) salts. For instance, the first
examples of CuHSO4 π-complexes and the direct Cu(I)∙∙∙F(SiF62−) interaction have been
observed in copper π-compounds with 1-allylbenzotriazole [13, 14] and with allyl-substituted
1,3,4-thiadiazoles [7, 15]. In this context, investigation of coordination behavior of allyl
derivatives of some polyazoles with respect to Cu(I) in the presence of anionic Pearson`s hard
−
−
bases (BF4 , ClO4 , SO42−, etc.) [16] deserves special attention. Moreover, recently an
appearance of high second and third order NLO susceptibilities was observed for copper(I)
π-complexes with 1-allyloxybenzotriazole [4], 3-allyl-2-(allylimino)-1,3-thiazolidin-4-one and
5-(allylthio)-1-(3,5-dimethylphenyl)-1H-tetrazole ligands [17, 18].
Despite the fact that tetrazole molecules are well established ligands for 3d-metal
complexation [19, 20], only some π-complexes of Cu(I) with allyl derivatives of tetrazole have
been studied hitherto [2, 21, 22], which could be caused by complicated conditions of their
preparation by classical methods. In order to examine coordinating behavior of S-allyl
derivatives of different 1-(aryl)-1H-tetrazoles-5-thioles regarding Cu(I), this article describes
synthesis
and characterization of four
novel
[Cu2(Matht)2(H2O)2](BF4)2
(1),
[Cu2(Chmatht)2(СlO4)2] (2), [Cu(Tfmatht)2]BF4 (3) and [Cu(Tfmatht)(NH2SO3)(MeOH)] (4)
2

π-complexes with 1-(4-methylphenyl)- (Matht), 1-(3-chloro-4-methylphenyl)- (Chmatht) and
1-[2-(trifluoromethyl)phenyl]- (Tfmatht) 5-(allylthio)-1H-tetrazoles.
2. Experimental
2.1. Materials and instrumentation
Unless otherwise mentioned, all chemicals were obtained from Sigma Aldrich and used without
1
purification. H NMR spectra of Matht, Chmatht and Tfmatht were recorded on a Varian
Mercury 400 instrument (400 MHz for 1H) with tetramethylsilane (TMS) or a deuterated solvent
as an internal reference. Single-crystal data were collected on a Rigaku AFC7 diffractometer
equipped with a Mercury CCD area detector, graphite monochromated MoKα radiation. Raman
spectra from crystals of 1-4 were recorded with a Horiba Jobin–Yvon LabRAM HR spectrometer
with the use of the 632.81 nm excitation line of a He-Ne laser (17 mW). Carbon, hydrogen,
nitrogen and sulfur contents for Matht, Chmatht and Tfmatht as well as for 1-4 were determined
using a CHNS elemental analyzer vario EL cube (Elementar) operating in the CHNS mode (see
Supplementary Materials).
2.2. Preparation of organic ligands
The target ligands IV (Matht (a), Chmatht (b) and Tfmatht (c)) were synthesized from 4-methyl
(I a), 3-chloro-4-methyl- (I b) and 2-(trifluoromethyl)aniline (I c) by several procedures
(scheme 1) [23-25]. The commercially available aniline I (0.01 mole) was dissolved in the
minimum amount of benzene and treated with carbon disulphide (0.01 mole, 0.70 mL) and
triethylamine (0.01 mole, 1.40 mL). The solution was cooled to 0 C and left for 5 days. After
complete precipitation of the triethylammonium dithiocarbamate salt, the solution was filtered.
The solid was washed with anhydrous ether and air dried for about 10 min. The salt was then
dissolved in about 7.5 mL of chloroform, treated with 1.4 mL of triethylamine and cooled to
0 C. To the solution was added ethyl chloroformate (0.01 mole, 1.02 mL) dropwise over a
15 min period under intense stirring. The resulting solution was stirred at 0 C for 10 min and
allowed to warm to room temperature for 1 h. The chloroform solution was washed with 3M
HCI and twice with water and was dried over Na2SO4. The chloroform was evaporated and the
aryl isothiocyanate II was distilled in vacuo.
3

The obtained isothiocyanate II (0.005 mole) was mixed with water (10 ml) and NaN3
(0.011 mole, 0.715 g) and refluxed with intense stirring until the suspension disappeared. The
solution was cooled to room temperature and washed with TBME. Water was separated and
acidified with 3M HCI (Caution! The HN3 elevation). The sediment of 1H-tetrazole-5-thiol III
was separated by the filtration and used for alkylation without further purification.
The 1H-tetrazole-5-thiol III (0.004 mole) was dissolved in solution of KOH (0.004 mole,
0.224 g) in ethanol (10 mL). To the solution allyl bromide (0.005 mole, 0.43 mL) was added and
the mixture was heated at 50 C for 1 h. Solvent removed in vacuo and to the residue was added
water 5 mL and dichloromethane 10 mL. Dichloromethane was separated and removed to give
target ligand IV.
1-(4-Methylphenyl)-5-[(prop-2-en-1-yl)sulfanyl]-1H-tetrazole, C11H12N4S (Matht), m.p.
34 C; 1Н NMR (400 MHz, DMSO-d6), δ, p.p.m. 7.46 (d, J = 8.2 Hz, 2H, HPh-3,5), 7.42 (d, J =
8.2 Hz, 2H, HPh-2,6), 5.97 (td, J = 16.8, 7.0 Hz, 1H, =CH), 5.36 (d, J = 17.0 Hz, 1H, CH2=), 5.18
(d, J = 9.8 Hz, 1H, CH2=), 3.99 (d, J = 7.0 Hz, 2H, CH2), 2.46 (s, 3H, CH3).
1-(3-Chloro-4-methylphenyl)-5-[(prop-2-en-1-yl)sulfanyl]-1H-tetrazole,
C11H11ClN4S
1
(Chmatht), m.p. 47 C; Н NMR (400 MHz, DMSO-d6), δ, p.p.m. 7.62 (s, 1H, HPh-2), 7.54 (d,
J = 8.2 Hz, 1H, HPh-5), 7.45 (d, J = 8.2 Hz, 1H, HPh-6), 5.99 (td, J = 17.0, 7.0 Hz, 1H, =CH),
5.39 (d, J = 17.0 Hz, 1H, CH2=), 5.20 (d, J = 9.9 Hz, 1H, CH2=), 4.02 (d, J = 7.0 Hz, 2H, CH2),
2.48 (s, 3H, CH3).
5-[(Prop-2-en-1-yl)sulfanyl]-1-[2-(trifluoromethyl)phenyl]-1H-tetrazole,
C11H9F3N4S
(Tfmatht), m.p. 63 C; 1Н NMR (400 MHz, DMSO-d6), δ, p.p.m. 8.03 (d, J = 7.3 Hz, 1H, HPh-3),
7.98-7.88 (m, 2H, HPh-4,5), 7.71 (d, J = 7.3 Hz, 1H, HPh-6), 5.94 (td, J = 16.8, 7.2 Hz, 1H, =CH),
5.36 (d, J = 16.8 Hz, 1H, CH2=), 5.18 (d, J = 9.9 Hz, 1H, CH2=), 3.98 (d, J = 6.9 Hz, 2H, CH2).
4

CS
2
NCS
N H
Et 3 N
2
NaN
H 2
3
O
1. ClCOOEt
Et 3 N
R
R
1
R
R
1
3
3
R
R
2
2
2. HCl
II a, b, c
I a, b, c
N
S
N
N
N
N
N
N
N
B r
KOH
EtOH
S H
R
R
1
3
R
R
3
1
R
2
R
2
IV a, b, c
III a, b, c
R
= R
=
R 3 = CH
I- IVa ( Matht ) :
H,
1
2
3
R
= H, R
=
R 3 = CH
Cl,
I- IVb (
Chmatht ) :
1
2
3
: R = CF 3 , R = R = H
)
I- IVc ( Tfmatht
1
2
3
Scheme 1. Synthesis of the tetrazole ligands.
2.3. Synthesis of copper(I) π-complexes
Crystals of complexes were obtained under conditions of alternating-current electrochemical
synthesis [26] starting from the alcohol solution of the appropriate organic ligand and copper(II)
salt.
2.3.1. Preparation of [Cu2(Matht)2(H2O)2](BF4)2 (1). To 2.5 mL of n-propanol solution of
Cu(BF4)2·6H2O (1.000 mmol, 0.345 g) 2.0 mL of n-propanol solution of Matht (0.689 mmol,
0.160 g) was added. The prepared grass-green solution was placed into a small 5 mL test-tube
and then copper-wire electrodes in cork were inserted. By the application of alternating-current
tension (frequency 50 Hz) of 0.4 V for 3 days, good quality colorless crystals of 1 (bis(µ-η2-1-(4-
methylphenyl)-5-[(prop-2-en-1-yl)sulfanyl]-1H-tetrazole)-diaqua-di-copper(I)
bis(tetrafluoroborate)) appeared on copper electrodes. The formed crystals are easily detached
from the electrode and accumulate at the bottom of the test-tube, from which they were isolated
by the filtration. The yield was 0.028 g (10%). Decompose with partial melting at 283 C.
2.3.2. Preparation of [Cu2(Chmatht)2(СlO4)2] (2). To 2.0 mL of n-propanol solution of
Cu(ClO4)2·6H2O (0.800 mmol, 0.296 g) 2.0 mL of n-propanol solution of Chmatht (0.791 mmol,
5

0.211 g) was added. By the application of alternating-current tension (frequency 50 Hz) of 0.6 V
for 7 days, the turquoise slightly turbid solution was discolored and good quality colorless
crystals of 2 (bis(µ-η2-1-(3-chloro-4-methylphenyl)-5-[(prop-2-en-1-yl)sulfanyl]-1H-tetrazole)-
bis((perchlorato-O))-di-copper(I)) appeared on copper electrodes. The formed crystals were
isolated as in the previous example. The yield was 0.085 g (25%). Decompose with
microexplosion at 230 C.
2.3.3. Preparation of [Cu(Tfmatht)2]BF4 (3). To 2.5 mL of n-propanol solution of
Cu(BF4)2·6H2O (1.000 mmol, 0.345 g) 2.0 mL of n-propanol solution of Tfmatht (0.900 mmol,
0.258 g) was added. The resulting green solution was subjected to alternating-current tension
(frequency 50 Hz) of 0.4 V for 4 days. Good quality colorless crystals of 3 (bis(µ-η2-5-[(prop-2-
en-1-yl)sulfanyl]-1-[2-(trifluoromethyl)phenyl]-1H-tetrazole)-copper(I)
tetrafluoroborate)
appeared on copper electrodes. The formed crystals were isolated as in the previous examples.
The yield was 0.114 g (35%). Decompose at 289 C.
2.3.4. Preparation of [Cu(Tfmatht)(NH2SO3)(MeOH)] (4). To 3.0 mL of a saturated methanol
solution of Cu(NH2SO3)2 1.5 mL of methanol solution of Tfmatht (0.700 mmol, 0.200 g) was
added. The resulting yellow-green slightly turbid solution was subjected to alternating-current
tension (frequency 50 Hz) of 0.6 V for 10 days. Good quality colorless crystals of 4 (methanol-
(µ-η2-5-[(prop-2-en-1-yl)sulfanyl]-1-[2-(trifluoromethyl)phenyl]-1H-tetrazole)-(sulfamato-N)-
copper(I)) appeared on copper electrodes, from which they were detached by mechanical
removal. The yield was 0.084 g (25%). Melt with partial decomposition at 155 C.
2.4. Crystallographic studies
The crystallographic parameters and summaries of data collection for 1-4 are presented in
table 1. The collected diffraction data were processed with the Rigaku CrystalClear software
suite program package [27]. Structures 1-3 were solved by direct methods with the use of SIR-92
program (implemented in the program package WinGX [28, 29]) and structure 4 was solved by
ShelXT program. All structures were refined by least squares method on F2 by the ShelXL
program with the following graphical user interface of OLEX2 [30-32]. Full–matrix least–
squares refinements based on F2 were carried out for the positional and thermal parameters for
6

−
all non-hydrogen atoms. In 1, three fluorine atoms of BF4 anion are disordered over two sites
and refined anisotropically with occupancy of 0.5. In 3, fluorine atoms of -CF3 group are
disordered over two sites with an occupancy ratio of 0.83(2):0.17(2). Positions of O-bonded H
atoms in 1 were derived from the Fourier difference syntheses and refined isotropically with
OH fixed distance. Positions of the other H atoms in 1-4 were treated as riding atoms and
refined with E–H fixed distances. The figures were prepared using DIAMOND 3.1 software
[33]; the ellipsoids are drawn at 40% probability level.
2.5. Nonlinear optical measurements
Third harmonic generation (THG) studies were performed using Nd:YAG laser with pulse
duration 10 ns and frequency reception 10 Hz. An interferometric filter at 355 nm was used for
spectral separation of the third harmonic with respect to the fundamental beams. A rotating
Glahn prism was used for tuning of the fundamental energy density and photomultiplier with
relaxation about 1 ns is used for the THG detection.
2.6. Computational methods
All calculations were performed on the DFT/B3LYP/cc-PVDZ level [34, 35] using the
GAMESS(US) program package [36]. A basis set with effective core potentials (ECPs) was
applied for the copper atoms. The initial geometries, derived from the crystal structures, were
assumed to have C1 symmetry and were utilized for the geometry optimization. The equilibrium
geometries obtained were used for the Forces Constants matrix calculation. Then polarizability
tensor was calculated and the resulting Raman activities (Si) were converted to Raman intensities
(Ii) using the relationship from the intensity theory of Raman scattering [37, 38].
3. Results and discussion
3.1. Crystal structures
In crystal structure of [Cu2(Matht)2(H2O)2](BF4)2 (1) the organic molecule acts as a tridentate
chelate-bridging π,σ-ligand being attached to the metal by means of two nucleophilic N3 and N4
atoms of the tetrazole core and the C=C bond from S-allyl group (see figure 1 and table 2). These
three active sites form a basal surrounding of the Cu(I) in its trigonal pyramidal arrangement; the
fourth apical position is occupied by H2O molecule. As a result, copper(I) atoms links up the two
7

adjacent Matht molecules into centrosymmetric cationic [Cu2(Matht)2(H2O)2]2+ dimer containing
two six-membered CuC4SN (considering the C=C bond as one coordinating site) and one six-
membered Cu2N4 rings.
The analogous [Cu2(L)2(H2O)2]2+ dimers have been found earlier in two π-complexes of
CuBF4 with 1-phenyl- and 1-(4-chlorophenyl)-5-(allylthio)-1H-tetrazoles [39]. Due to a
−
significant hardness in HSAB terms of the fluorine atoms of BF4 , they are substituted by OH2 in
−
the metal coordination environment, therefore outer-sphere BF4 anions are bound by the
−
O−H···F(BF4 ) hydrogen bonds only (table S1, Supplementary Materials). All these facts are in
a good agreement with the Pearson`s HSAB principles [16], according to which the heterocyclic
N atoms, possessing border line basicity as well as soft C=C base, are more favorable to
−
coordination with soft Cu(I) ion than H2O or even such hard bases as BF4 or SiF62− anions.
Addition of m-Cl substituent at the 4-methylphenyl group does not prevent Chmatht
molecule in structure of [Cu2(Chmatht)2(СlO4)2] (2) from formation of centrosymmetric
[Cu2(Chmatht)2]2+ dimers. Copper(I) coordination environment is arranged in a similar way to 1
and includes in basal plane N atoms and C=C bond (see figure 2 and table 2). The apical position
−
of the polyhedron is occupied by O atom of the ClO4 anion. It is worth noting that analogous
stable “building blocks” [Cu2(L)2]2+ were recently observed in structures of Cu(I) π-complexes
with allyl-substituted 1,3,4-thiadizoles, 1,3,4-oxadiazoles and 1,2,4-triazoles [15, 40, 41].
In the case of o-substituted trifluoromethylphenyl derivative, Tfmatht, another mode of
coordination was observed; both [Cu(Tfmatht)2]BF4 (3) and [Cu(Tfmatht)(NH2SO3)(MeOH)] (4)
appeared to be monomers (see figures 3 and 4). In the structure of 3, Cu(I) atom lies on the two-
fold axis and adopts disordered tetrahedral environment, comprised of two C=C bonds from allyl
groups and two N4 atoms from Tfmatht molecules (see table 3). It is clear that the presence of
CF3 group in ortho-position of the phenyl ring significantly reduces nucleophilic activity of
tetrazole N atoms. Most probably, not only electronic factors, but also significant steric
hindrance prevents participation of N3 in the tetrazole in metal coordination. Also, such
structural stress affects the geometry of the ligand: the dihedral angle between the planes of
tetrazole and phenyl rings equals 78.0 in 3, in comparison to 41.1 in 1 and 67.3 in 2.
Simultaneous coordination of two N atoms and two C=C bonds to the same Cu(I) center
occurs relatively rarely; hitherto, it has been found only in a few copper(I) π-complexes in the
−
−
−
presence of BF4 , ClO4 and PF6 anions only [42-45].
8

−
The N atom in the NH2SO3 anion successfully competes with the heterocyclic moiety,
replacing tetrazole N atom in Cu(I) coordination environment. Due to a significant increase of
dz2-energy, this anion completely excludes another Tfmatht molecule from the metal
coordination sphere in structure of [Cu(Tfmatht)(NH2SO3)(MeOH)] (4). The Cu(I) atom
environment in 4 is close to a trigonal pyramid. It is composed of two basal N atoms and allylic
C=C bond, while the fourth apical position is occupied by O atom of CH3OH molecule (see
−
table 3). Although the NH2SO3 anion is able to be bound to Cu(I) simultaneously by N and O
atoms [17, 46], the hydroxyl group of the methanol molecule appeared to be more favorable in 4.
The last fact may be caused by a significant role of N−H···O−S hydrogen contacts involving
NH2SO3 fragments (table 4). The S−O···H−O hydrogen contacts between the sulfamate anion
and hydroxyl group of methanol together with N−H···O−S bonding connect individual
[Cu(Tfmatht)(NH2SO3)(MeOH)] complex fragments into infinite chains.
One may note that the efficiency of Cu(I)(C=C) interaction in 1, 2 and 4 is confirmed by
rather short Cu–m (m – a middle point of the C=C bond) distances and rather large C–Cu–C
angles (figure captions 1-4). The fact that Cu(I) deviates from the base of the trigonal pyramid by
0.36 Å (1), 0.19 Å (2) and 0.44 Å (4) (as well as the angle between the C=C bond and base plane
is 24.1 (1), 10.8 (2) and 5.4 (4)) also confirms this conclusion [2].
3.2. Computational results
In order to get deeper insight into the molecular structures of 1-4, calculations at B3LYP/cc-
pVDZ level were performed. The experimental molecular geometries were utilized as an initial
point for geometry optimization. The optimized structures are shown in figures S1-S4,
Supplementary Materials, and selected geometrical parameters for every compound in
comparison to the experimental ones are provided below each figure. Equilibrium geometries
appeared to be very close to the experimental values; so, for 1 and 2 at equilibrium point
CuN4Cu hexagon is slightly bent towards chair conformation in the way that Cu atoms protrude
from the plane formed by four nitrogen atoms, giving dihedral angles N3iN4N3Cu and
N4iN3N4Cui of 13.0
 and 12.7 in 1 and 9.3 and 9.6 in 2.
The first HOMO/LUMO orbitals are represented in figure 5. There is very interesting
difference related to the localization of the latter. In 1 and 2, the HOMOs are located mostly
along the π-bond between the allyl groups and Cu atoms and ligands/anions bounded to metal
9

centers, whereas the LUMOs are situated on the tetrazole and aromatic rings. The same
−
distribution is preserved in 4, where most of the HOMO is located around the SO3NH2 anion. A
rather different case is observed for 3, where the HOMO is predominately localized on the
tetrazole, sulphur atom, allyl group and copper, and the LUMO is predominately localized on
π-bonds between allyl groups and copper atom indicating lack of electron density on these
atoms, which allows for further substitution of a Tfmatht ligand by another σ-donor ligand. The
HOMO-LUMO gaps for all the compounds have high values of at least 4.68 eV (2) (see
figure 5), indicating that these compounds could adsorb light in UV diapason. The equilibrium
geometries were utilized for calculation of the Raman spectra; absence of the imaginary
frequencies confirmed the optimizations convergence to real minimum.
3.3. Raman spectra
The Raman spectra of 1-3 are shown in figure 6, this of 4 was not possible to collect due to too
intense fluorescence. The band assignments were made on the basis of computed Raman spectra
−
(see tables S1-S4). The bands due to BF4 anions in 1 and 3 were assigned in agreement with the
literature sources [47].
The computed and experimental spectra appeared to be in good agreement with the
exception of 2, where discrepancies in relative intensities appeared. Presumably, the difference is
caused by lattice contribution to resulting polarizability tensor in the experiment, whereas this
effect is not taken into account while calculating bands of a single molecule. The allyl ν(C=C)
band, which is most frequently considered to be characteristic for these compounds, is found to
appear at 1537, 1528 and 1591 cm-1 in the spectra of 1, 2 and 3, respectively. Apparently, the
bond Cu–(C=C) in 3 is the weakest among these compounds, as a significant red shift is
expected in a case of strong bonding [15, 48].
3.4. Nonlinear optical properties
The results of third order nonlinear optical studies are presented in figure 7. Well-known BiB3O6
crystals were applied as a standard; the observed THG signal intensity appeared to comprise
about 30% with respect to BiB3O6. The other samples show very similar magnitudes and the
difference between them is within the experimental errors. Among the compounds investigated,
the intensity of THG follows the order 3>4>1 in all the ranges of pump laser powers.
10

Presumably, monomeric Cu(I) units are more favorable targets for THG studies. It might be
suggested that by means of optimization of π,σ-donating ligands, better performance might be
achieved.
4. Conclusion
The utilization of alternating-current electrochemical technique allowed us to prepare and isolate
single crystals of copper(I) π,σ-coordination compounds containing 1-(4-methylphenyl)- (Matht),
1-(3-chloro-4-methylphenyl)- (Chmatht) and 1-[2-(trifluoromethyl)phenyl]- (Tfmatht)
5-(allylthio)-1H-tetrazoles. The coordination environment of Cu(I) was found to be affected by
presence of electron acceptor group in a ligand and by the nature of anion/ligands according to
Pearson's HSAB principles. These factors promote a complete change of the Cu(I) surrounding,
leading to either dimeric complexes or to monomeric in a case of [Cu(Tfmatht)2]BF4 and
[Cu(Tfmatht)(NH2SO3)(MeOH)]. The geometries and HOMO/LUMO orbitals were analyzed by
means of ab initio DFT calculations. Detailed analysis of the Raman spectra of the compounds
was made on the basis of computed vibrational spectra. The conclusions of this work open new
avenues for intentional preparation of Cu(I) compounds with predetermined geometry, which
might be suitable for further investigation of nitrogen-rich compounds. The studied samples
possess the THG efficiency equal to about 30% with respect to the well-known BiB3O6 crystals.
Supporting information
CCDC 1857210, 1857211, 1857212 and 1857213 contain the supplementary crystallographic
data for this paper. Copies of the data can be obtained free of charge on applications to the
Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (Fax: int. code +(1223)336–033;
E-mail for inquiry: fileserv@ccdc.cam.ac.uk).
Acknowledgements
The authors gratefully acknowledge the financial support by Slovenian Research Agency
(ARRS) and by Sechenov First Moscow State Medical University, Russia.
11

References
[1]
E. Cariati, E. Lucenti, C. Botta, U. Giovanella, D. Marinotto, S. Righetto. Coord. Chem.
Rev., 306, 566 (2016).
[2]
[3]
[4]
Y. Slyvka, E. Goreshnik, O. Pavlyuk, M. Mys’kiv. Cent. Eur. J. Chem., 11, 1875 (2013).
X.-S. Wang, H. Zhao, Y.-H. Li, R.-G. Xiong, X.-Z. You. Top. Catal., 35, 43 (2005).
Yu. Slyvka, A.A. Fedorchuk, E. Goreshnik, G. Lakshminarayana, I.V. Kityk, P. Czaja,
M. Mys’kiv. Chem. Phys. Lett., 694, 112 (2018).
[5]
[6]
[7]
P. Brandt, M.J. Södergren, P.G. Andersson, P.-O. Norrby. J. Am. Chem. Soc., 122, 8013
(2000).
P.J. Perez, M.M. Diaz-Requejo, Comprehensive Organomet. Chem. III Vol. 2. Elsevier:
Amsterdam (2007); p 153.
B. Ardan, V. Kinzhybalo, Yu. Slyvka, O. Shyyka, M. Luk’yanov, T. Lis, M. Mys’kiv.
Acta Crystallogr., Sect. C, C73, 36 (2017).
[8]
[9]
I. Iakovidis, I. Delimaris, S.M. Piperakis. Mol. Biol. Intern., 1 (2011).
C. Marzano, M. Pellei, S. Alidori, A. Brossa, G.G. Lobbia, F. Tisato, C. Santini. J. Inorg.
Biochem., 100, 299 (2006).
[10] F. Tisato, C. Marzano, M. Porchia, M. Pellei, C. Santini. Med. Res. Rev., 30, 708 (2010).
[11] A. Gupte, R.J. Mumper. Cancer Treat. Rev., 35, 32 (2009).
[12] M.-J. Zhang, H.-X. Li, H.-Y. Li, J.-P. Lang. Dalton Trans., 45, 17759 (2016).
[13] E.A. Goreshnik, Yu.I. Slyvka, M.G. Mys'kiv. Inorg. Chim. Acta, 377, 177 (2011).
[14] E.A. Goreshnik, A.A. Vakulka, Yu.I. Slyvka, M.G. Myskiv. J. Organomet. Chem., 710,
1 (2012).
[15] E.A. Goreshnik, G. Veryasov, D. Morozov, Yu. Slyvka, B. Ardan, M.G. Mys’kiv.
J. Organomet. Chem., 810, 1 (2016).
[16] R.G. Pearson. J. Am. Chem. Soc., 85, 3533 (1963).
[17] Yu.I. Slyvka, A.A. Fedorchuk, N.T. Pokhodylo, T. Lis, I.V. Kityk, M.G. Mys’kiv.
Polyhedron, 147, 86 (2018).
[18] A.A. Fedorchuk, Yu.I. Slyvka, E.A. Goreshnik, I.V. Kityk, P. Czaja, M.G. Mys’kiv.
J. Mol. Struct., 1171, 644 (2018).
[19] G. Aromi, L.A. Barrios, O. Roubeau, P. Gamez. Coord. Chem. Rev., 255 485 (2011).
12

[20] A. Tabacaru, C. Pettinari, S. Galli, Coord. Chem. Rev., 372, 1 (2018).
https://doi.org/10.1016/j.ccr.2018.05.024.
[21] Yu. Slyvka, E. Goreshnik, N. Pokhodylo, O. Pavlyuk, M. Mys’kiv, Acta. Chim. Slov., 63,
399 (2016). http://dx.doi.org/10.17344/acsi.2016.2486
[22] Yu.I. Slyvka. J. Struct. Chem., 56, 998 (2015).
[23] J.E. Hodgkins, W.P. Reeves. J. Org. Chem., 29, 3098 (1964).
[24] K. Takeda, K. Tsuboyama, K. Torii, M. Murata, H. Ogura. Tetrahedron Lett., 29, 4105
(1988).
[25] T. Kamiya, K.Tanaka, Y Shiokawa, Product and preparation of 1H-tetrazole-5-thiol
derivatives. Google Patents: 1978.
[26] Yu.I. Slyvka, O.V. Pavlyuk, M. Yu. Luk'yanov, M.G. Mys’kiv. Ukraine Patent UA
118819, Bull. No. 16, August 28, 2017.
[27] Rigaku Corporation, The Woodlands, Texas, USA (1999) CrystalClear.
[28] A. Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, M.C. Burla, G. Polidori, M.
Camalli. J. Appl. Cryst., 27, 435 (1994).
[29] L.J. Farrugia. J. Appl. Cryst., 32, 837 (1999).
[30] G.M. Sheldrick. Acta Crystallogr., Sect. A, A71, 3 (2015).
[31] G.M. Sheldrick. Acta Crystallogr., Sect. C, C71, 3 (2015).
[32] O.V. Dolomanov, L.J. Bourhis, R.J. Gildea, J.A.K. Howard, H. Puschmann. J. Appl.
Cryst., 42, 339 (2009).
[33] Diamond - Crystal and Molecular Structure Visualization Crystal Impact - Dr. H. Putz
and Dr. K. Brandenburg GbR, Kreuzherrenstr. 102, 53227 Bonn, Germany
http://www.crystalimpact.com/diamond
[34] A.D. Becke. J. Chem. Phys., 98, 5648 (1993).
[35] C. Lee, W. Yang, R. Parr. Phys. Rev. B., 37, 785 (1988).
[36] M.W. Schmidt, K.K. Baldridge, J.A. Boatz, S.T. Elbert, M.S. Gordon, J.H. Jensen, S.
Koseki, N. Matsunaga, K.A. Nguyen, S. Su, T.L. Windus, M. Dupuis, J.A. Montgomery.
J. Comp. Chem., 14, 1347 (1993).
[37] P.L. Polavarapu. J. Phys. Chem., 94, 8106 (1990).
[38] G. Keresztury, S. Holly, G. Besenyei, J. Varga, A. Wang, J.R. Durig. Spectrochim. Acta,
Part A, 49, 2007 (1993).
13

[39] Yu. Slyvka, N. Pokhodylo, R. Savka, Z. Mazej, E. Goreshnik, M. Mys’kiv. Chem. Met.
Alloys, 3, 201 (2010).
[40] Y. Slyvka, E. Goreshnik, G. Veryasov, D. Morozov, M. Luk'yanov, M. Mys'kiv.
Polyhedron, 133, 319 (2017).
[41] O.R. Hordiichuk, V.V. Kinzhybalo, E.A. Goreshnik, Y.I. Slyvka, M.S. Krawczyk, M.G.
Mys’kiv. J. Organomet. Chem., 838, 1 (2017).
[42] J.J. Allen, A.R. Barron. Dalton Trans., 878 (2009).
[43] M. Maekawa, K. Sugimoto, T. Okubo, T. Kuroda-Sowa, M. Munakata. Inorg. Chim.
Acta, 467, 204 (2017).
[44] M. Munakata, S. Kitagawa, H. Shimono, H. Masuda. Inorg. Chem., 30, 2610 (1991).
[45] S. Fraysse, A. von Zelewsky, H. Stoeckli-Evans. New J. Chem., 25, 1374 (2001).
[46] O.P. Mel'nik, M.G. Mys'kiv, V.N. Davydov. Russ. J. Coord. Chem., 29, 339 (2003).
[47] A.S. Quist, J.B. Bates, G.E. Boyd. J. Chem. Phys., 55, 2836 (2003).
[48] B. Ardan, Y. Slyvka, E. Goreshnik, M. Mys’kiv. Acta Chim. Slov., 60, 484 (2013).
14

Table 1. Crystal data and structure refinement for 1-4.
1
2
3
4
CCDC number
Empirical formula
Formula weight (g/mol)
Temperature, K
Wavelength (Å)
Crystal system
Space group
1857210
1857211
1857212
C22H18BCuF10N8S2
722.94
1857213
C12H15CuF3N5O4S2
477.95
C22H28B2Cu2F8N8O2S2
801.34
C22H22Cl4Cu2N8O8S2
859.47
200(2)
200(2)
200(2)
200(2)
0.71069
0.71069
0.71069
0.71069
Triclinic
P-1
Monoclinic
C2/c
Monoclinic
P21/a
Monoclinic
C2/c
Unit cell dimensions (Å, °)
a, Å
20.431(6)
7.659(3)
20.896(6)
90
9.000(3)
12.681(4)
10.474(4)
21.402(6)
90
7.241(3)
8.213(3)
16.215(5)
75.03(3)
79.09(3)
78.59(3)
903.4(6)
2
b, Å
14.959(4)
c, Å
11.870(4)
α, °
90
97.70(3)
90
96.42(3)
96.93(3)
90
, °
90
, °
V, Å3
3240.3(19)
4
1588.0(9)
2821.9(16)
4
Z
2
Calculated density (g/cm3)
Absorption coeff. (mm-1)
F(000)
1.643
1.797
1.702
1.757
1.523
1.866
1.019
1.500
1616
864
1448
484
Crystal size (mm)
Color
0.11 × 0.1 × 0.06
Colorless
2.0 – 27.7
6251
0.14 × 0.12 × 0.1
Colorless
1.7 – 28.4
6213
0.12 × 0.1 × 0.1
Colorless
1.9 – 29.3
3091
0.11 × 0.08 × 0.07
Colorless
2.6 – 29.1
8770
Theta range for data collection (°)
Measured reflections
Used in refinement
Free parameters
R[F2 > 2σ(F2)], wR(F2), S
3125
3027
3091
3776
243
208
210
248
0.0622, 0.1941, 1.115
0.0579, 0.1813, 1.129
0.0522, 0.1563, 0.966
0.0464, 0.1289, 1.121
15

Table 2. Selected bond distances (Å) and angles (°) in 1 and 2.
Bond
Angle
1
2
1
2
Cu–N3i
Cu–N4
Cu–O1
Cu–m
1.988(4)
2.013(4)
2.217(4)
1.946(5)
1.353(7)
1.968(4)
1.975(4)
2.397(4)
1.923(5)
1.353(8)
C3–Cu–C4
m–Cu–N3i
m–Cu–N4
N3i–Cu–N4
N3i–Cu–O1
38.4(2)
38.8(2)
127.6(2)
114.6(2)
107.9(2)
92.9(1)
130.0(2)
116.7(2)
110.4(2)
87.6(2)
C3–C4
m – a mid-point of C3–C4 double bond. Symmetry code: (i) 1–x, 1–y, 1–z.
16

Table 3. Selected bond distances (Å) and angles (°) in 3 and 4.
3
Cu–N4
Cu–m
2.059(3)
2.068(3)
1.321(5)
C3–Cu–C4
m–Cu–mi
35.4(1)
124.1(2)
108.7(2)
105.4(2)
102.6(2)
C3–C4
m–Cu–N4
m–Cu–N4i
N4–Cu–N4i
4
Cu–N4
Cu–N5
Cu–O4
Cu–m
2.020(3)
2.055(3)
2.160(3)
1.944(3)
1.358(5)
C3–Cu–C4
m–Cu–N4
N4–Cu–N5
N4–Cu–O4
N5–Cu–O4
38.5(1)
117.1(1)
96.8(1)
95.5(1)
102.0(1)
C3–C4
m – is a mid-point of C3–C4 double bond. Symmetry code: (i) 1–x,
y, 0.5–z.
17

Table 4. Geometry of selected hydrogen bonds in 1 and 4.
Atoms involved
Symmetry
Distances, Å
H···A
Angle, deg
D−H···A
D···H
D···A
D−H···A
1
O1−H1A···F4
O1−H1B···F1A
O1−H1B···F2A
O1−H1B···F1B
1–x, 2–y, 1–z
0.86(1)
0.86(1)
0.86(1)
0.86(1)
1.89(1)
2.36(5)
2.21(4)
2.06(5)
2.748(5)
3.12(2)
3.01(1)
2.85(2)
174(6)
148(8)
154(8)
151(8)
4
O4−H4···O1
N5−H5A···O2
N5−H5B···O3
1–x, –y, 1–z
1–x, 1–y, 1–z
1–x, –y, 1–z
0.87
0.91
0.91
1.84
2.35
2.26
2.699(4)
3.194(3)
3.159(3)
169
154
172
18

Graphical Abstract
19

Figure captions
Figure 1. Cationic [Cu2(Matht)2(H2O)2]2+ dimer in crystal structure 1. Symmetry code: (i) 1–x,
1–y, 1–z.
20

Figure 2. Molecular fragment of crystal structure 2. Symmetry code: (i) –x, 1–y, 1–z.
21

Figure 3. Fragment of crystal structure 3. Symmetry code: (i) 1–x, y, 0.5–z. One of the two
disordered positions of а fluorine atom with lower s.o.f. value is shown in semitransparent mode.
22

Figure 4. Molecular fragment of crystal structure 4 (a) and a part of polymeric chain of earlier
studied complex [Cu(C12H14N4S)NH2SO3]n [17] (b).
23

Figure 5. HOMO (left) and LUMO (right) orbitals of compounds 1-4. For the clarity of
representation, only cation of compound 1 is shown. HOMO-LUMO band gaps have the values
of 4.94 eV (1), 4.68 eV (2), 5.17 eV (3) and 5.87 eV (4).
24

Figure 6. Raman spectra of compounds 1-3. Detailed band lists and assignments are provided in
Supplementary Materials.
25

Figure 7. Dependence of the THG versus the fundamental power energy.
26