A two-dimensional Cu^I framework incorporating the 1-phenyl-1H-1,2,3,4-tetra­zole-5-thiol ligand

The new two-dimensional coordination polymer, poly[(μ₄-1-phenyl-1H-1,2,3,4-tetra­zole-5-thiol­ato)copper(I)], [Cu(C₇H₅N₄S)]_n, has been prepared under solvothermal conditions by reacting CuBr with 1-phenyl-1H-1,2,3,4-tetra­zole-5-thiol (Hptt) in an aceto­nitrile and acetone solution. In the crystal structure, each Cu^I ion is coordinated by two N atoms and two S atoms from four ptt⁻ ligands, and each ptt⁻ ligand links four Cu^I ions to form two-dimensional layers which lie parallel to the (100) plane. These layers stack along the [100] direction via van der Waals inter­actions.

S1. Introduction

The synthesis and design of functional d⁸/d¹⁰ transition-metal complexes with a closed-shell electronic configuration have drawn enormous inter­est in recent years because of their intriguing coordination architectures and potential applications in various fields including catalysis, photochemistry, fluorescence and biological properties (Yue et al., 2008, 2010; Yam et al., 1997; Lin et al., 2010). Among these materials, Cu^I–metal complexes have been studied intensively because of their abundant resources, low cost and nontoxic properties compared with noble metal complexes, e.g. Re^I, Os^II, Ir^III, Rh^I and Pt^II (Yam et al., 1999, 2002; Harvey et al., 1988; White-Morris et al., 2002). Furthermore, Cu^I is a favourable and fashionable ion for the construction of coordination polymers because of its highly diversified and flexible coordination number and geometry, as well as its ready coordination with various donor atoms, such as O, S, N, P and I, which facilitate the discovery of inter­esting structural motifs.

Much effort has focused on using organosulfur and organo­nitro­gen ligands as bridging units between Cu^I sites. For example, Cu₆(btt)₆ and Cu₄(btt)₄ (btt is 2-benzo­thia­zole­thiol) feature slightly distorted o­cta­nuclear [Cu₆] and tetra­nuclear [Cu₄] cores, respectively, in which all the Cu^I ions are coordinated by two S atoms and one N atom from three btt ligands with nearly trigonal planar coordination geometries (Yue et al., 2009). Cu₃(4-pyt)₃ (4-pyt is pyridine-4-thiol­ate) exhibits a three-dimensional network in which two crystallographically independent Cu^I ions feature nearly trigonal planar and slightly distorted tetra­hedral coordination environments (Han et al., 2009).

In recent years, complexes based on tetra­zole and its derivatives have attracted much attention due to the ligand's highly flexible coordination mode (Bai et al., 2006). We are inter­ested in the synthesis of complexes between Cu^I and 1-phenyl-1H-tetra­zole-5-thiol (Hptt), where both the N and S atoms act as electronic donors, about which little is known compared with other systems containing tetra­zole. Our exploratory studies led to one new complex, poly[(µ₄-1-phenyl-1H-1,2,3,4-tetra­zole-5-thiol­ato)copper(I)], [Cu(ptt)]_n, (I), and the synthesis and crystal structure is reported herein.

S2. Experimental

S2.1. Synthesis and crystallization

All analytical grade chemicals were obtained commercially and used without further purification. Elemental analyses (C, H and N) were performed using a PE2400 II elemental analyzer. Compound (I) was prepared by solvothermal methods. CuBr (0.2 mmol, 29 mg) and Hptt (0.2 mmol, 36 mg) were added to a solution (8 ml) composed of aceto­nitrile and acetone in a 1:1 ratio. The solution was sealed in a Teflon-lined stainless steel reactor. The mixture was heated at 350 K for 3 d, and then cooled to room temperature over a period of 1 d, affording a yellow solution, which was evaporated under ambient conditions to give yellow crystals of (I) (yield 54.2%, 26 mg, based on Cu). Analysis calculated for C₇H₅CuN₄S (%): H 2.09, C 34.92, N 23.27; found: H 2.07, C 34.79, N 23.21.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms were placed in calculated positions, with C—H = 0.93 Å, and refined in the riding-model approximation, with U_iso(H) = 1.2U_eq(C).

S3. Results and discussion

The X-ray single-crystal diffraction study reveals that [Cu(ptt)]_n (ppt is 1-phenyl-1H-1,2,3,4-tetra­zole-5-thiol­ate), (I), crystallizes in the monoclinic space group P2₁/c. As shown in Fig. 1, there is one crystallographically independent Cu^I ion and one ppt^- ligand in the asymmetric unit. Each Cu^I ion is coordinated by two N atoms and two S atoms from four different ptt^- ligands to give a distorted tetra­hedral coordination environment, which is very similar to that of [Cu^I(ppt)(C₁₄H₈N₂S₅)]ClO₄.CHCl₃ (Jeannin et al., 1979) [what is C₁₄H₈N₂S₅?]. A similar tetra­hedral coordination geometry about Cu^I ions has been reported in many complexes, such as [Cu₄I(ptt)₃(Hptt)₃]₄ and (Ph₃P)₃Cu₄(mmt)₄ (mmt is 5-mercapto-1-methyl-1,2,3,4-tetra­zole; Wei et al., 2009; Nöth et al., 1998). As listed in Table 2, the Cu—N and Cu—S bond lengths are comparable to those reported in the above-mentioned Cu^I complexes. Each ptt^- ligand acts as a µ₄-bridging ligand linking four Cu^I ions. Two adjacent N atoms in the tetra­zole unit of the ptt^- ligand coordinate in a monodentate fashion to two Cu^I ions so that the ligand bridges these metal centres, while the S atom acts as a bridging bidentate metal linker bridging two further Cu^I ions. This connectivity results in the formation of two-dimensional (2D) [Cu(ptt)]_n layers which lie parallel to the (100) plane (Fig. 2).

It is instructive to consider the substructures apparent within the layers. The 2D layer can be considered as being built from two halves, where each half-layer is composed of one-dimensional (1D) zigzag [Cu–S–Cu–S] chains running parallel to the [001] direction inter­linked through the 1-phenyl­tetra­zole units (Fig. 3a). Two half-layers are further inter­connected via Cu—N bonds to form the 2D [Cu(ptt)]_n layer. Within the 2D layer, there is a ladder, propagating along the [010] direction, composed of alternating centrosymmetric ten-membered [Cu–S–Cu–N–N–Cu–S–Cu–N–N] rings (A type) and eight-membered [Cu–N–C–S–Cu–N–C–S] rings (B type) fused by sharing the S–Cu–N edges (Fig. 3b). Between two adjacent ladders, neighbouring ten-membered rings only share a common Cu atom and no atoms are common to two eight-membered rings. At the same time, crosslinking of the A- and B-type rings along the [001] direction leads to another series of seven-membered [Cu–N–C–S–Cu–N–N] rings (C type), which also propagate along the [010] direction by fusing with each other through the Cu1—N1 bond (Fig. 3c). The seven-membered rings are fused with adjacent eight- and ten-membered rings.

The shortest Cu···Cu distance within the [Cu(ptt)]_n layer is 3.504 (3) Å for Cu1···Cu1(-x+1, -y+2, -z+1), which is longer than the sum of the van der Waals radii of two Cu^I atoms (2.80 Å; Bondi et al., 1964). The shortest contact between neighbouring [Cu(ptt)]_n layers is the H5···H6(-x, y+1/2, -z+1/2) distance of 2.64 Å. Thus, only van der Waals inter­actions exist between the 2D [Cu(ptt)]_n layers (Fig. 2).

It is inter­esting to compare the coordination modes of tetra­zole-5-thiol units. As shown in Fig. 4, the tetra­zole-5-thiol units in many reported complexes exhibit a wide variety of coordination modes: µ₁-1κS (mode A), µ₂-1κS:2κN (mode B), µ₃-1,2κS:3κN (mode C), µ₄-1,2κS:3κN:4κN' (mode D) and µ₅-1,2,3κS:4κN:5κN' (mode E). For example, coordination mode A has been reported in [Cu₄I(ptt)₃(Hptt)₃]₄ and coordination mode B is found in [Zn(mmt)₂]_n, while the mmt ligand adopts coordination mode C in (Ph₃P)₃Cu₄(mmt)₄ and [Cd(mmt)₂]_n (Wei et al., 2009; Wang et al., 2008; Nöth et al., 1998). Inter­estingly, the ptt^- ligand simultaneously features modes A and C in [Cu₄I(ptt)₃(Hptt)₃]₄ (Wei et al., 2009). Coordination modes D and E are found in Ag₆Cl₂(mmt)₄[H₄SiMo₁₂O₄₀](H₂O)₂ and [Ag₈(mmt)₄][SiW₁₂O₄₀].H₂O, respectively (Wang et al., 2012; Yang et al., 2012). The ptt ligand in (I) adopts coordination mode D.

Related literature

For related literature, see: Bai et al. (2006); Bondi (1964); Han et al. (2009); Harvey & Gray (1988); Jeannin et al. (1979); Lin et al. (2010); Nöth et al. (1998); Wang et al. (2008, 2012); Wei et al. (2009); White-Morris, Olmstead, Jiang & Balch (2002); Yam (2002); Yam & Lo (1999); Yam et al. (1997); Yang et al. (2012); Yue et al. (2008, 2009, 2010).

Computing details

Data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The structure of part of a layer in (I), showing the Cu^I ion, the ligand coordination and the atom-numbering scheme. In the electronic version of the paper, the C, N, S and Cu atoms are drawn as gray, blue, yellow and brown spheres, respectively. [Symmetry codes: (i) x, y-1, z; (ii) x, -y+1/2, z+1/2; (iii) -x+1, y-1/2, -z+1/2; (iv) -x+1, -y+1, -z; (v) x, -y+1/2, z-1/2; (vi) -x+1, y+1/2, -z+1/2; (vii) x, -y+3/2, z-1/2; (viii) x, -y+3/2, z+1/2; (ix) x, y+1, z; (x) -x+1, -y+1, -z+1; (xi) -x+1, -y+2, -z+1; (xii) -x+1, y+3/2, -z+1/2; (xiii) -x+1, -y+2, -z.]
	Fig. 2. A projection of the packing of (I) along the [010] direction, showing the layers end-on.
	Fig. 3. Some substructures within the [Cu(ptt)]n layer: (a) the Cu–S–Cu–S chains along [001]; (b) alternating fused type A and B rings; (c) the fused type C rings.
	Fig. 4. Coordination modes of the tetrazole-5-thiol unit found in the literature and in (I) (mode D).

Poly[(µ₄-1-phenyl-1H-1,2,3,4-tetrazole-5-thiolato)copper(I)]

Crystal data

[Cu(C7H5N4S)]	Z = 4
Mr = 240.75	F(000) = 480
Monoclinic, P21/c	Dx = 1.883 Mg m^−3
Hall symbol: -p2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 17.344 (15) Å	µ = 2.77 mm^−1
b = 6.509 (5) Å	T = 293 K
c = 7.522 (6) Å	Block, yellow
β = 90.790 (17)°	0.22 × 0.16 × 0.16 mm
V = 849.1 (12) Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	1923 independent reflections
Radiation source: fine-focus sealed tube	1534 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.063
ω scan	θmax = 27.4°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −22→22
Tmin = 0.580, Tmax = 0.674	k = −7→8
6033 measured reflections	l = −9→9

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.133	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.064P)^2 + 0.6784P] where P = (Fo^2 + 2Fc^2)/3
1923 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 1.00 e Å^−3
0 restraints	Δρmin = −0.68 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.45089 (3)	0.89282 (8)	0.31726 (8)	0.0302 (2)
S1	0.38690 (6)	0.72397 (16)	0.07158 (14)	0.0249 (3)
N1	0.4350 (2)	0.3554 (5)	0.2096 (5)	0.0255 (8)
N2	0.4019 (2)	0.1840 (6)	0.2784 (5)	0.0280 (8)
C5	0.0783 (4)	0.5611 (13)	0.1896 (10)	0.068 (2)
H5	0.0263	0.5957	0.1861	0.082*
N4	0.3110 (2)	0.3928 (5)	0.2228 (5)	0.0275 (8)
N3	0.3276 (2)	0.2016 (6)	0.2880 (6)	0.0346 (9)
C1	0.3772 (2)	0.4863 (6)	0.1711 (5)	0.0223 (8)
C2	0.2317 (3)	0.4576 (8)	0.2081 (7)	0.0334 (10)
C3	0.2100 (3)	0.6500 (9)	0.2644 (8)	0.0451 (13)
H3	0.2463	0.7428	0.3082	0.054*
C6	0.1015 (4)	0.3707 (11)	0.1311 (10)	0.0612 (18)
H6	0.0652	0.2788	0.0856	0.073*
C7	0.1790 (3)	0.3151 (10)	0.1396 (8)	0.0457 (13)
H7	0.1952	0.1867	0.1007	0.055*
C4	0.1321 (4)	0.7021 (12)	0.2540 (9)	0.0634 (19)
H4	0.1161	0.8316	0.2903	0.076*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0329 (3)	0.0239 (3)	0.0340 (4)	0.0003 (2)	0.0029 (2)	−0.0022 (2)
S1	0.0342 (6)	0.0193 (5)	0.0211 (5)	0.0015 (4)	−0.0017 (4)	−0.0004 (4)
N1	0.0291 (19)	0.0186 (17)	0.029 (2)	−0.0019 (14)	0.0006 (16)	−0.0021 (15)
N2	0.0318 (19)	0.0232 (18)	0.029 (2)	−0.0013 (15)	0.0034 (16)	0.0013 (15)
C5	0.032 (3)	0.108 (6)	0.064 (5)	0.013 (4)	−0.001 (3)	0.009 (4)
N4	0.0265 (18)	0.0229 (18)	0.033 (2)	0.0022 (14)	0.0016 (16)	0.0031 (16)
N3	0.037 (2)	0.026 (2)	0.041 (2)	−0.0001 (17)	0.0020 (18)	0.0100 (18)
C1	0.027 (2)	0.020 (2)	0.020 (2)	0.0022 (16)	−0.0030 (16)	−0.0014 (16)
C2	0.029 (2)	0.040 (3)	0.031 (2)	0.004 (2)	0.0044 (19)	0.005 (2)
C3	0.038 (3)	0.054 (3)	0.043 (3)	0.014 (2)	0.002 (2)	−0.005 (3)
C6	0.036 (3)	0.086 (5)	0.062 (4)	−0.015 (3)	−0.009 (3)	0.008 (4)
C7	0.036 (3)	0.054 (3)	0.047 (3)	−0.006 (3)	0.001 (2)	−0.001 (3)
C4	0.050 (3)	0.082 (5)	0.059 (4)	0.034 (4)	0.005 (3)	0.000 (4)

Geometric parameters (Å, º)

Cu1—N1^i	2.007 (4)	C5—H5	0.9300
Cu1—N2^ii	2.096 (4)	N4—C1	1.361 (5)
Cu1—S1^iii	2.3511 (18)	N4—N3	1.367 (5)
Cu1—S1	2.4079 (18)	N4—C2	1.442 (6)
S1—C1	1.728 (4)	C2—C3	1.376 (7)
S1—Cu1^iv	2.3511 (18)	C2—C7	1.395 (8)
N1—C1	1.344 (5)	C3—C4	1.393 (8)
N1—N2	1.360 (5)	C3—H3	0.9300
N1—Cu1^v	2.007 (4)	C6—C7	1.394 (8)
N2—N3	1.296 (5)	C6—H6	0.9300
N2—Cu1^vi	2.096 (4)	C7—H7	0.9300
C5—C6	1.377 (10)	C4—H4	0.9300
C5—C4	1.392 (11)
N1^i—Cu1—N2^ii	119.61 (14)	N3—N4—C2	119.3 (4)
N1^i—Cu1—S1^iii	121.32 (12)	N2—N3—N4	105.4 (3)
N2^ii—Cu1—S1^iii	102.17 (11)	N1—C1—N4	106.5 (4)
N1^i—Cu1—S1	108.18 (12)	N1—C1—S1	125.8 (3)
N2^ii—Cu1—S1	97.13 (12)	N4—C1—S1	127.7 (3)
S1^iii—Cu1—S1	105.02 (7)	C3—C2—C7	122.6 (5)
C1—S1—Cu1^iv	96.47 (14)	C3—C2—N4	120.5 (5)
C1—S1—Cu1	97.05 (15)	C7—C2—N4	116.9 (5)
Cu1^iv—S1—Cu1	123.67 (7)	C2—C3—C4	118.2 (6)
C1—N1—N2	106.5 (3)	C2—C3—H3	120.9
C1—N1—Cu1^v	129.4 (3)	C4—C3—H3	120.9
N2—N1—Cu1^v	124.1 (3)	C5—C6—C7	120.3 (6)
N3—N2—N1	112.0 (4)	C5—C6—H6	119.8
N3—N2—Cu1^vi	118.2 (3)	C7—C6—H6	119.8
N1—N2—Cu1^vi	128.5 (3)	C6—C7—C2	118.1 (6)
C6—C5—C4	120.5 (6)	C6—C7—H7	121.0
C6—C5—H5	119.8	C2—C7—H7	121.0
C4—C5—H5	119.8	C5—C4—C3	120.3 (7)
C1—N4—N3	109.6 (4)	C5—C4—H4	119.9
C1—N4—C2	131.0 (4)	C3—C4—H4	119.9

Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x, y+1, z; (iii) x, −y+3/2, z+1/2; (iv) x, −y+3/2, z−1/2; (v) −x+1, y−1/2, −z+1/2; (vi) x, y−1, z.