Trivalent copper and indium heterometallic complex with dithiocarbamate and iodide ligands

Article abstract of DOI:10.1016/j.molstruc.2019.127478

The heterometallic Cu–In complex salt [Cu(III) (dtc)₂][In(III)I₄](1) (dtc = S₂CNEt₂, diethyldithiocarbamate) was prepared by reactions of Cu(II) (dtc)₂ and In(III)I₃ in benzene solution. As a redox reaction, Cu(II) (dtc)₂ was oxidized to [Cu(III) (dtc)₂]⁺, and In(III)I₃ was changed to [In(III)I₄]^?. The square?planar Cu(III)S₄ local symmetry of 1 involves a distorted octahedral coordination environment via long?range intermolecular interactions and represents a new one-dimensional structure of [Cu(III) (dtc)₂]⁺ units. The crystal packing system of 1 consists of many [Cu(III) (dtc)₂]⁺ chains surrounded by six parallel chains without solvent molecules. The infrared spectra of 1 showed a higher-frequency C–N thioureide bond in Cu(III) (dtc)₂ than that of pristine Cu(II) (dtc)₂, which has a lower oxidation state due to the Cu(II) center.

Full text of DOI:10.1016/j.molstruc.2019.127478

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Trivalent copper and indium heterometallic complex with dithiocarbamate and iodide
ligands
Hyun−Jong Lee, Seonho Jung, Ji−Hyun Cha, Dongsik Nam, Wonyoung Choe, Duk
−Young Jung
PII:
S0022-2860(19)31587-X
DOI:
https://doi.org/10.1016/j.molstruc.2019.127478
MOLSTR 127478
Reference:
To appear in: Journal of Molecular Structure
Received Date: 24 September 2019
Revised Date: 15 November 2019
Accepted Date: 24 November 2019
Please cite this article as: Hyun−Jong. Lee, S. Jung, Ji−Hyun. Cha, D. Nam, W. Choe, Duk−Young.
Jung, Trivalent copper and indium heterometallic complex with dithiocarbamate and iodide ligands,
Journal of Molecular Structure (2019), doi: https://doi.org/10.1016/j.molstruc.2019.127478.
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2019/11/25
Journal of Molecular Structure
Trivalent Copper and Indium Heterometallic Complex with Dithiocarbamate and Iodide Ligands
a
a
a
b
b
a*
Hyun−Jong Lee , Seonho Jung , Ji−Hyun Cha , Dongsik Nam , Wonyoung Choe and Duk−Young Jung
a
Department of Chemistry, Sungkyun Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan
University, Suwon, Gyeonggi−do 16419, Korea
b
Department of Chemistry, Ulsan National Institute of Science and Technology, 50 UNIST−gil, Ulsan 44919, Korea
Abstract
The heterometallic Cu−In complex salt [Cu(III)(dtc) ][In(III)I ](1) (dtc = S CNEt , diethyldithiocarbamate)
2
4
2
2
was prepared by reactions of Cu(II)(dtc) and In(III)I in benzene solution. As a redox reaction, Cu(II)(dtc)
2
2
3
+
−
was oxidized to [Cu(III)(dtc) ] , and In(III)I was changed to [In(III)I ] . The square−planar Cu(III)S local
2
3
4
4
symmetry of 1 involves a distorted octahedral coordination environment via long−range intermolecular
+
interactions and represents a new one-dimensional structure of [Cu(III)(dtc) ] units. The crystal packing
2
+
system of 1 consists of many [Cu(III)(dtc) ] chains surrounded by six parallel chains without solvent
2
molecules. The infrared spectra of 1 showed a higher-frequency C−N thioureide bond in Cu(III)(dtc) than
2
that of pristine Cu(II)(dtc) , which has a lower oxidation state due to the Cu(II) center.
2
Keywords: copper; trivalent; indium; dithiocarbamate; iodide; heterometallic.
1
. Introduction
Chalcopyrite semiconductors, particularly Cu-In-Ga-S or Se compounds (CIGS), have advantageous
properties for solar applications, such as direct band-gap and high optical absorption coefficient.[1]
Photovoltaic devices of CIGS typically have been fabricated in the form of polycrystalline films,
demonstrating a maximum solar energy conversion efficiency of 22.4%.[2] The conventional fabrication
technologies of CIGS thin films utilize sputter or co-evaporator technologies that involve the high-cost
vacuum method.[3] The development of low-cost and high-efficiency CIGS thin-film photovoltaic cells is one
of the major challenges for commercialization and involves pyrolysis of metal chlorides containing thin layers,
nanoparticle colloidal inks, or electrodeposition directly on the molybdenum electrode in liquid media .[4-16]
Molecular precursors for the solution process of CIGS thin films commonly involve ligands with sulfur or
1

selenium elements, such as thiolate,[17] dithiooxalate,[18] and selenolate.[19] Dithiocarbamate derivatives are
good candidates as molecular precursors of semiconducting metal sulfides as they contain sulfur atoms
available to coordinate metal ions.[20-26] CuInS nanocrystals with chalcopyrite phase were prepared from
2
the complex of Cu, In, and diethyldithiocarbamate.[26] Dithiocarbamate can stabilize metal ions with various
oxidation states due to the large atomic orbital of sulfur atoms. Interestingly, copper complexes of
dithiocarbamates were electrochemically oxidized from monovalent to divalent and trivalent oxidations
states.[27-31]
Trivalent copper-dithiocarbamate compounds are rare, and only
a
few examples such as
[
Cu(III)(dtc) ][Fe(III)Cl ] and [Cu(III)(Medtc) ][ClO ] (Medtc = dimethyldithiocarbamate) have been
2
4
2
4
reported.[32-35] Although Cu(II)(dtc) has been studied well, little is known of the chemical reactions of
2
In(III)I as a metal halide, especially for heterometallic salt compounds. Herein, we report the synthesis of
3
[
Cu(III)(dtc) ][In(III) ] as a possible single precursor source of Cu, In, and S.
2 4
2
2
. Experimental section
.1. Synthesis of Cu(II)(dtc)2
Cu(II)(dtc) was prepared by the reported method.[36-38] The solution was prepared by dissolution of 1.3526
2
g (6.00 mmol) of NaS CNEt ·3H O (98 %) in 100 mL distilled water, and the residue was filtered. A 30 mL
2
2
2
aqueous solution containing 0.4291 g (2.52 mmol) of CuCl ·2H O (99 %) was slowly added dropwise under
2
2
stirring. The brown precipitate was washed three times with distilled water and recrystallized three times by
dichloromethane and ethanol. Crystalline powder was obtained at a yield of 92.40 %. IR spectral peaks were
−
1
recorded in (cm ) at 2983 (m), 2931 (w), 2873 (w), 1504 (s), 1435 (m), 1377 (w), 1354 (w), 1273 (m), 1207
m), 1147 (m), 1074 (m), 997 (m), 914 (m), 846 (m), and 779 (m).
(
2
.2. Synthesis of [Cu(III)(dtc) ][In(III)I ] (1)
2 4
A benzene solution of 50 mL was prepared with 0.5001 g (1.11 mmol) InI (99.999 %, anhydrous) and added
3
to a 50-mL solution of 0.3651 g (1.01 mmol) Cu(II)(dtc) with stirring for 3 days at room temperature. Then,
2
n−hexane was added to the black benzene solution to obtain a dark−green precipitate that was dissolved in
dichloromethane, and the residue was filtered. The dark−green solution with the precipitate was recrystallized
with n−hexane three times at a yield of 49.3%. The dark green needle-shaped crystals were grown in
dichloromethane and benzene at ~ 2ꢀC for 3 days.
2
.3. Materials and physical measurements
All reagents were purchased from Alfa Aesar. Elemental analysis was performed on a Flash2000 (Thermo
2

Fisher Scientific, Germany) elemental analyzer. Inductively coupled plasma optical emission spectrometry
(
(
ICP−OES) was performed using an Agilent 5100 ICP−OES spectrometer. Energy−dispersive spectroscopy
EDS) was performed using a Schottky field emission scanning electron microscope (SEM, JSM−7100F)
operating at 15kV. Infrared spectra were recorded with a Bruker Vertex 70 FT−IR, with MIRacle attenuated
−
1
total reflection (ATR) (Pike), using a germanium crystal in the range of 5000−400 cm . Thermal gravimetric
curve and differential thermal analyses were recorded with a Seiko Exstar 6100.
2
.4. X−ray crystallography
Single−crystal X−ray diffraction (SCXRD) data (Table 1) of [Cu(III)(dtc) ][In(III)I ] were collected at the 6D
2
4
beam line (2017−3rd−6D−A026) at the Pohang Accelerator Laboratory (PAL), Korea. Diffraction data were
obtained with the Rayonix Ms225−HS detector at 100K (λ=0.65303 Å). MxDC software and HKL2000 [39]
were used for data collection and cell refinement. The crystal structure was refined with the SHELXTL
program package [40]. Molecular graphics were prepared using VESTA [41].
3
. Result and discussion
The In(III)I is mild oxidizing agent and reduced to In(II)I . Because In(II) is unstable, indium dihalides
3
2
In(II)X (X = Cl, Br, I) occur disproportionation to In(I) and In(III) as following [42],
2
2-
-
-
[
In(II) X ] ⇄ [In(I)X ] + [In(III)X ] .
2
6
2
4
The expected redox reaction equation is
Cu(II)(dtc) + 2In(III)I → [Cu(III)(dtc) ][In(III)I ] + In(II)I
2
2
3
2
4
In(II)I ⇄ 0.5In(I)I + 0.5In(III)I
2
3
3
.1. Unit cell of [Cu(III)(dtc) ][In(III)I ] (1)
2 4
+
The heterometallic salt [Cu(III)(dtc) ][In(III)I ](1) consists of cationic [Cu(III)(dtc) ] and anionic
2
4
2
−
+
[
In(III)I ] ,with a monoclinic system of P2 /n (Table 1). Four [Cu(III)(dtc) ] units are located in a unit cell,
4 1 2
−
on the 8 corners, 4 edges, 2 faces, and a body. On the contrary, four [In(III)I ] units are positioned on the
4
+
body of the unit cell surrounding the central [Cu(III)(dtc) ] , as shown in Fig. 1(a).
2
The square−planar local symmetry of Cu(III) is achieved with four sulfur atoms of dtc ligands in
+
[
Cu(III)(dtc) ] (blue) arranged in a parallel direction to each other along the a axis at four corners and one
2
−
center. The tetrahedral coordination of In(III) with four iodides in [In(III)I ] (purple) describes the separated
4
polyatomic anions in 1. The asymmetric unit denoted as a dotted circle in Fig. 1(b) has one blue and one
+
−
purple polyhedron, respectively corresponding to [Cu(III)(dtc) ] and [In(III)I ] , separated from each other.
2
4
3

+
−
3
.2. Local structure of [Cu(III)(dtc) ] and [In(III)I ]
2 4
+
The [Cu(III)(dtc) ] units of 1 possess a square−planar structure with one-dimensional chain connectivity
2
through weak interactions between copper(III) and non-bonding sulfurs belonging to other square-planar units,
+
as shown in Fig. 2(a). The electrostatic repulsion of cationic complexes of [Cu(III)(dtc) ] units results in
2
these weak interactions; although the square planar units demonstrate parallel stacking arrangement in the
crystal structure. The pristine divalent precursor of neutral Cu(II)(dtc) complexes has a strongly bound dimer
2
of [Cu(II)(dtc) ] , indicating a covalent bond between two Cu(II)(dtc) square planar units, where copper sites
2
2
2
demonstrate the distorted square pyramidal symmetry of Cu(II)S (Fig. 2(b)).[37-38]
5
+
Two sites of [Cu(III)(dtc) ] show Cu(1)−S and Cu(2)−S bond lengths of 2.198(2)−2.209(2) Å and
2
2
.211(2)−2.207(2) Å, respectively (Table 2). The shorter bond lengths of trivalent Cu(III)−S in 1 were
compared with the longer lengths of 2.3080(4)−2.3369(4) Å of Cu−S in divalent Cu(II)(dtc) [38]. The bond
2
+
angles of the two coppers S−Cu(1,2)−S in the slightly distorted square planar (D ) [Cu(III)(dtc) ] units were
4h
2
the same at 79.49(8)° and 100.51(8)°, producing local planar sites of copper with two-fold symmetry (Table 3).
The bond angles of S−Cu−S on divalent Cu(II)(dtc) are 76.679 (14)°, 77.124 (14)°, 101.715 (15)°, 101.592
2
(
15)°, respectively [38], indicating greater distortion resulting from the dimeric interaction between two Cu(II)
+
…
and two dtc ligands. 1 has a polymeric [Cu(III)(dtc) ] chain forming long−range intermolecular Cu S
2
interactions of 3.396(3) Å and 3.575(3) Å along the a−axis, indicating weaker interactions than that of 2.851
−
Å of Cu(II)(dtc) [38]. The [In(III) ] possesses In−I bond lengths of 2.7060(11) − 2.7220(9) Å and I−In−I
2
4
bond angles of 108.00(3) − 111.46(3)ꢀ, producing a distorted tetrahedral (T ) structure (Fig. 2(c)). The
d
+
−
[
Cu(III)(dtc) ] chain is surrounded by four [In(III) ] units, of which the electrostatic interactions are the main
2 4
+
driving force to bind [Cu(III)(dtc) ] .
2
3
.3 Calculation of the oxidation state of Cu center.
The shorter bond lengths of Cu-S also demonstrate the high oxidation state of Cu. The bond-valence sum
model explains the relationship between bond length and bond valence according to the equation S = exp[(r0 -
r ) / B]. The empirical constants are determined by ensuring the best fit to the valence sum rule of V = ∑ S .
ij
i
j ij
The summation is over all the bonds with oxidation state value V and bond valence S [43].
i
ij
The new bond valence sum model has a general relation between oxidation state V and r . V = (1 + 20 / n)
i
ij
i
∑ nj R/r – 4 [44]. The R value of Cu(III)-S is ~0.651 and the coordination number n is 4. The calculated
ij
oxidation state V for eight bond lengths r in Table 2 are 3.091 for Cu(1)-S(1~2) and 3.073 for Cu(2)-S(3~4),
i
ij
respectively.
Figure 3 shows three crystal structures of trivalent copper-containing dithiocarbamate complex compounds,
4

+
−
+
−
+
chain types [Cu(III)L ] [A ] and dimeric [Cu(III)L ] [A ] . The interconnecting chains of [Cu(III)(dtc) ] in
∞
∞
2
2
2
1
(Fig. 3(a)) are also found in the heterometallic salt of [Cu(III)(dtc) ][Fe(III)Cl ] (Fig. 3(b)), with
2 4
…
intermolecular Cu S distances of 3.251(2) Å and 3.294(2) Å [35]. In addition, the [Cu(III)(Medtc) ] [ClO ]
4 2
2
2
…
shown in Fig. 3(c) possesses an isolated dimeric molecular structure that has Cu S interactions of 3.649(2) Å
…
and Cu O interactions of 2.753(3) Å [35].
3
.4. Interconnecting structures of chain type Cu−dithiocarbamate complexes
Most of the copper−dithiocarbamate complexes have square-planar symmetry with small or large distortion
allowing interconnection with other copper−dithiocarbamates, such as monomer, dimer, and infinite chain
types. When the divalent Cu(II)(dtc) dimeric molecule was placed on the bc plane, the Cu(II)(dtc)
2
2
+
monomeric unit rotated about 12° in C−Cu−C angle, as shown in Fig. 4(a). The angle of [Cu(III)(dtc) ] in the
2
one−dimensional type of 1 was about 73° (Fig. 4(b)), deviating significantly from the angle of the pristine
+
molecule of Cu(II)(dtc) . The angle of [Cu(III)(dtc) ] in [Cu(III)(dtc) ][Fe(III)Cl ] was 88° (Fig. 4(c)), similar
2
2
2
4
+
−
to that of 1. However, dimeric [Cu(III)(Medtc) ] [ClO ] (Fig. 4(d)) demonstrates a zero rotational angle,
2
2
4
2
similar to the divalent Cu(II)(dtc) dimeric molecule, ascribed to the strong inter-complex Cu−S binding and
2
shorter alkyl group of the dithiocarbamate ligand.
+
The infinite [Cu(III)(dtc) ] chain of 1 arranged around the center of the unit cell is surrounded by six parallel
2
chains with similar inter-chain distances when the crystal packing system is shown along the a-axis (Fig. 5(a)).
Chain packing with a hexagonal arrangement in 1 is compared with that of monoclinic
[
Cu(III)(dtc) ][Fe(III)Cl ] (Fig. 5(b)), which has four nearest neighbor chains in a distorted cubic packing
2 4
system. Although both compounds undergo crystal growth in benzene solution and produce black-green
needle shapes, 1 has no benzene molecules in the crystal structure, supporting formation of different
+
[
Cu(III)(dtc) ] chain types of these compounds.
2
The previous Cu−dithiocarbamate complexes had versatile types of crystal structures based on oxidation state
of Cu or alkyl substitution and were classified into three groups of polymeric, dimeric, and monomeric
structures. The first type has one−dimensional polymeric chains that form through interactions of Cu and
anion. The Cu−S square−planar complexes of neutral Cu(II)(Medtc) are overall parallel with a weak steric
2
…
effect, forming a chain through Cu S interactions of 3.159(2) Å between neighboring copper complexes. [45]
(
Fig. 6(a)).
…
1
has a polymeric chain structure with weaker inter−complex interactions, resulting in longer Cu S distances
of 3.396(3) Å and 3.575(3) Å (Fig. 3(a)). The heterometallic salt of [Cu(III)(dtc) ][Fe(III)Cl ] is stabilized by
2
4
+
oxidation of neutral Cu(II)(dtc) into [Cu(III)(dtc) ] with a one−dimensional polymeric chain, which
2
2
5

…
transformed to a weak Cu S connecting chain structure of 3.251(2) Å, as shown in Fig. 6 (b). On the other
−
hand, [Cu(III)(dtc) ][I ] contained [I ] anions that form the consecutive two-fold chain structure, which has a
2
3
3
triiodide anion directly bound between two trivalent copper centers, demonstrating the weakest interchain
…
…
interaction among three structures, as indicated by the Cu I distance of 3.477(1) Å and the long Cu S
distance of 5.344(4) [33] (Fig. 6c).
3
.5. Dimer and monomer structures of Cu−dithiocarbamate complexes
…
The second category of structures are dimers formed by Cu S interactions. The compounds of three examples
belong to this type, in which the compound with the strongest interaction is neutral dimeric Cu(II)(dtc) (Fig.
2
7
(a)), [Cu(III)(Medtc) ][ClO ] and [Cu(III)[Pydtc) ][ClO ]. The latter Cu(III)-containing compounds have
2 4 2 4
…
weak inter−complex interactions involving the long Cu S distances of 3.649(2) Å and 3.318(4) Å,
…
respectively [32]. [Cu(III)(Medtc) ][ClO ] has not only Cu S interactions, but also fills the octahedral
2
4
−
coordination of Cu(III) by [ClO ] anion interaction with Cu(III)−O of 2.753(3) Å [35], as shown in Fig. 7(b)
4
and Fig. 7(c).
The third type of structure of Cu−dithiocarbamate complexes is the monomer with direct bonding of Cu(III)
…
complexes and anions without inter−complex Cu S interaction, [Cu(III)(Prdtc) ][I ], which has square
2
5
−
pyramidal symmetry of the Cu(III) center, dithiocarbamate, and axial iodine of the [I ] anion (Fig. 7(d)) [34].
5
…
The Cu(III) I bond distance is 3.665(4) Å [34] , which is larger than that of the common covalent bond. In the
oxidation reaction, the chain structure of Cu(II)(Medtc) is changed to the dimeric structure between Cu(III)
2
−
and oxygen of the [ClO ] anion; however, the dimeric structure of Cu(II)(dtc) is transformed to the chain
4
2
structure without remarkable change of square planar copper−dithiocarbamate complexes.
.6. Infra-red spectra
3
−
1
Infrared spectra were observed in the range of 4000 ~ 600 cm . Three compounds, Na−dtc, Cu(II)(dtc) , and
2
…
[
Cu(III)(dtc) ][In(III)I ] (1), have similar IR spectra with ν(C N) and ν(C−S) observed in the regions of 1475
2
4
−
1
−1
~
1560 cm and 950 ~ 1050 cm , respectively (Fig. 8). Vibrations of ν(C−S) asymmetric stretching were also
−
1
+
observed at 985, 999, and 995 cm . Cu(II)(dtc) and [Cu(III)(dtc) ] demonstrate similar C−S bands, implying
2
2
that the C−S bonds do not change when Cu(II) is oxidized to Cu(III) in dithiocarbamate ligands [46-47].
Vibration of ν(C−N) asymmetric stretching called the ‘thioureide bond’ [27] were observed at 1477, 1504, and
−
1
1
550 cm for Na−dtc, Cu(II)(dtc) , and 1, respectively. Na−dtc shows the smallest vibration band at 1477
2
−
1
+
cm due to the ionic bond of Na −S inducing a weaker C−N bond than that of the others. Through oxidation
−
1
of Cu(II) into Cu(III), the C−N bond length decreased and shifted the peak from 1504 to 1550 cm . The
absorption bands of the thioureide bond in other Cu(III)−dithiocarbamates, e.g., [Cu(III)(dtc) ][Fe(III)Cl ] and
2
4
6

−
1
[
Cu(III)(dtc) ][ClO ], are observed at 1570 and 1560 cm , respectively [27].
2 4
3
.7. Thermal analysis
Thermal stabilities of Cu(II)(dtc) and 1 have been investigated under a N atmosphere from 25 to 800ꢀC. For
2
2
Cu(II)(dtc) , a one−step weight loss of 75.7% was observed from 206 to 323ꢀC in the TG curve, leaving a
2
residue of 19.1%, in agreement with previously reported data [48]. In the DTA curve of Cu(II)(dtc) , a first,
2
sharp, endothermic peak was observed at 200ꢀC and a second, broad peak at 296ꢀC (Fig. 6a). On the other
hand, the weight loss of 1 occurs in two temperature regions, the first from 164ꢀC to 262ꢀC showing weight
loss of 18.2% and the second from 281 to 674ꢀC with 70.4%. Thermal analysis shows that 1 has a melting
point of 166ꢀC at the first sharp endothermic peak and decomposition at 227ꢀC. When the compound 1 was
heated on 250˚C under argon atmosphere for 5 hours the XRD patterns show the mixed phases of CuInS and
2
Cu(I)I. Elemental analysis, ICP−OES, and energy−dispersive spectroscopy (Fig. S1) were performed on 1 to
determine the chemical composition, as is summarized in Table 5. The formula CuInS N C H I based on
4
2
10 20 4
single-crystal XRD data is compared with the chemical analyses producing the formula Cu1.00In1.04
S4.03N2.00C10.28H20.02 I4.11
.
4
. Conclusion
The Cu(III)In(III) heterometallic compound with a high oxidation state of Cu was successfully synthesized.
+
The one-dimensional connection of [Cu(III)(dtc) ] is a structural characteristic of 1, which was found as a
2
new structural type in Cu(III)-containing heterometallic compounds, demonstrating hexagonal packing of
+
polymeric chains. The bond lengths of Cu(III)–S and C−N in [Cu(III)(dtc) ] of 1 were systematically
2
exemplified and were used as very important criteria in observation of coordination environments and
oxidation states of copper in Cu−dithiocarbamate complexes.
Acknowledgements
This work was supported by an Energy Technology Development Program of the Korea Institute of Energy
Technology Evaluation and Planning (KETEP) grant (20163010012570).
Supplementary materials
Crystallographic data have been deposited with the CCDC. CCDC 1949607 contains the supplementary
crystallographic data for [Cu(III)(dtc) ][In(III)I ]. These data can be obtained free of charge via
2
4
7

https://www.ccdc.cam.ac.uk/, or from the Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-mail: deposit@ccdc.cam.ca.uk.
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1
2

Table. 1 Crystal data and structure refinement for [Cu(III)(dtc) ][In(III)I ] (1).
2
4
[
Cu(III)(dtc) ][In(III)I ] (1)
Compound
2
4
Empirical formula
C
10
H
20 Cu I
4
In N
2
S
4
─1
Formula wt/g mol
Wavelength/Å
Crystal system
Space group
a/Å
982.48
0.65303
Monoclinic
P2 /n
1
8.4690(17)
14.015(3)
21.809(4)
90
b/Å
c/Å
α/
°
°
β/
95.45(3)
γ/
°
90
Z
4
3
V/Å
2576.9(9)
2.532
5.301
-3
D
calc/g cm
-1
µ/mm
Θ range/°
1.589−25.000°
100(2)
T/K
Reflections collected
20 715
Observed reflections (I ≥ 2σ)
5765 [R(int) = 0.0943]
0.0943
R
int
R (F)
0.0510
2
R
w
(F )
Goodness-of-fit F
No. of parameters, restraints
0.1586
2
1.051
206, 0
-3
∆
ρmax, ∆ρmin/e Å
2.031; −2.353

Table. 2 Bond lengths (Å) for 1.
Bond
Length(Å)
Bond
Length(Å)
1.723(8)
1.724(8)
Cu(1)−S(1) 2.209(2)
Cu(1)−S(1a) 2.209(2)
Cu(1)−S(2) 2.198(2)
Cu(1)−S(2a) 2.198(2)
Cu(2)−S(3) 2.211(2)
Cu(2)−S(3a) 2.211(2)
C(1)−S(1)
C(1)−S(2)
C(1a)−S(1a) 1.723(9)
C(1a)−S(2a) 1.724(8)
C(1)−N(1) 1.306(11)
C(6)−N(2) 1.313(11)
2
2
.207(2)
.207(2)
Cu(2)−S(4)
Cu(2)−S(4a)
In−I
2.7065(10)
2
2
2
.7149(10)
.7220(9)
.7060(11)
Table. 3 Bond angle (°) for 1 and Cu(II)(dtc)2.
[
Cu(III)(dtc) ][In(III)I ] (1)
Cu(II)(dtc)2
2
4
Bond
Angle(°)
Bond
Angle(°)
Bond
Angle(°)
Bond
Angle(°)
1
1
1
08.43 (3)
08.00 (3)
11.46 (3)
7
7
9.49 (8)
9.49 (8)
79.46 (8)
79.46 (8)
100.54 (8)
100.54 (8)
76.679 (14)
77.124 (14)
101.592 (15)
101.715 (15)
S−Cu(1) −S
S−Cu(2) −S
I−In−I
S−Cu−S
1
1
00.51 (8)
00.51 (8)
111.50 (4)
1
1
09.08 (4)
08.39 (3)
This work
Reference [38]

-1
Table. 4 Infrared absorption frequencies (cm ) of C−S and C−N for selected Cu−dtc complexes.
ν(C−S)
ν(C−N)
References
this work
Na−dtc
985s
1477s
9
9
99s
97s
1504s
1506s
this work
[38,44]
Cu(II)(dtc)
2
[
Cu(III)(dtc)
2
][FeCl
4
]
-
-
1570s
1560s
1550s
[35]
[35]
[
Cu(III)(Medtc)
2
] [ClO ]
4
[
Cu(III)(dtc)
2
] [In(III)I
4
]
995s
this work
Table.5 Elemental analysis, ICP−OES, EDS and suggested chemical formula of 1.
Elemental analysis
ICP-OES
Cu
EDS
Element
C
H
N
S
In
I
In
Weight %
12.44
2.03
2.82
13.01
6.35
1.00
10.87
66.17
4.11
11.47
Mole ratio
10.28
20.02
2.00
4.03
1.04
1.00
Suggested experimental formula: Cu1.00In1.04
S
4.03
N
2.00
C
10.28
H
20.02 4.11
I
Calculated formula by X-ray crystallography: [Cu(dtc)
2
][InI
4
] = CuInS
4
N
2
C
10
H I
20 4

Fig. 1
(a)
(b)
Fig. 2
(a)
(b)
(c)
I
S
S
Cu(II)
In(III)
Cu(III)
Fig. 3
(b)
(c)
(a)

Fig. 4
(a)
(b)
(c)
(d)
7
3°
88°
0°
1
2°
Fig. 5
(a)
(b)
Fig. 6
5
.344(4) Å
(b)
(c)
(a)
3
.477(1) Å
3
.159(2) Å
3
.251(2) Å

Fig. 7
(
a)
(b)
(
d)
(
C)
3
.665(4)Å
.499(5)Å
3
.318(4)Å
5
Fig. 8

Fig. 9
(a)
(b)
Figure explanation
Fig. 1 (a) Unit cell of 1 and (b) its polyhedron representation. Cu(III)−S units of [Cu(III)(dtc) ] are
+
4
2
−
shown as blue square-planar and In(III)−I of [In(III)I ] as purple tetrahedral ones. Hydrogen, carbon
4
4
and nitrogen atoms are omitted for clarity.
+
Fig. 2 Molecular structures (a) [Cu(III)(dtc) ] cation, (b) dimeric structure of Cu(II)(dtc) and (c)
[
2
2
−
In(III)I ] anion. Hydrogen are omitted for clarity.
4
Fig. 3 The structures of (a) 1, (b) [Cu(III)(dtc) ][Fe(III)Cl ] and (c) [Cu(III)(Medtc) ][ClO ].
2
4
2
4
Hydrogen are omitted for clarity.
Fig. 4 Three dimensional arrangements and dihedral angles of (a) dimeric Cu(II)(dtc) (b)
2
,
+
+
+
[
[
Cu(III)(dtc) ] of 1, (c) [Cu(III)(dtc) ] of [Cu(III)(dtc) ][Fe(III)Cl ] and (d) [Cu(III)(Medtc) ] of
2 2 2 4 2
Cu(III)(Medtc) ][ClO ]. Hydrogen are omitted for clarity.
2
4
Fig. 5 Molecular packing systems of (a) 1, (b) [Cu(III)(dtc) ][Fe(III)Cl ] in the bc plane. Cu−S and
2
4
4
N−S units are shown as blue square−planar, InI units and FeCl are shown as purple and brown
2
4
4
tetrahedra.
…
Fig. 6 Polymeric chain types structures and inter-complex interactions through non-covalent Cu S
bond distances in (a) Cu(II)(Medtc) , (b) [Cu(III)(dtc) ][Fe(III)Cl ] and (c) Cu(III)(dtc) ][I ].
2
2
4
2
3
…
Fig.7 Structures and inter-complex interactions through non-covalent Cu S bond distances in
intermolecular interactions in dimeric (a) Cu(II)(dtc)2, (b) [Cu(III)(Medtc) ][ClO ], (c)
2
4
Cu(III)(Pydtc) ][ClO ] and monomeric (d) Cu(III)(Prdtc) ][I ].
2
4
2
5

Fig. 8 Infrared spectra of dtc compounds: (A) 1, (B) Cu(II)(dtc) and (C) Na−dtc complexes in the
2
−
1
selected range 700~3500cm .
Fig. 9 TGA−DTA curves of (a) Cu(II)(dtc) and (b) 1 obtained under control of 800 ꢀC in N at a rate
2
2
of 10 ꢀC /min.

Highlights
ꢀ
ꢀ
ꢀ
Heterometallic Cu and In compound with ligands of diethyldithiocarbamate(dtc) and iodine were
prepared as precursor of CuInS thin film.
2
The compound has trivalent Cu center of Cu-dtc and the crystal packing system has infinited Cu-S
chain.
The crystal structures of similar compounds with trivalent Cu-dtc are investigated.

Author Contribution Statement
Hyun−Jong Lee: Validation, Formal analysis, Investigation, Writing - Original Draft
Seonho Jung: Resources
Ji−Hyun Cha: Validation
Dongsik Nam: Resources
Wonyoung Choe: Resources
Duk−Young Jung: Project administration, Writing - Review & Editing

Declaration of interests
☒
The authors declare that they have no known competing financial interests or personal relationships
that could have appeared to influence the work reported in this paper.
☒
The authors declare the following financial interests/personal relationships which may be considered
as potential competing interests:
Hyun−Jong Lee, Seonho Jung, Ji−Hyun Cha, Dongsik Nam, Wonyoung Choe and Duk−Young Jung