The structural definition of some novel adducts of stoichiometry CuX:dpex:MeCN (2:1:1)(n), X = (pseudo-) halogen, dppx = Ph2E(CH2)xEPh2, E = P, As, Sb

Article abstract of DOI:10.1016/j.ica.2005.12.019

Single-crystal X-ray studies have defined the structures of a number of novel adducts of the form CuX:dpex (2:1), X = (pseudo-)halide, dpex = bis(diphenylpnicogeno)alkane, Ph₂E(CH₂)_xEPh₂, E = P, As, of diverse types, solvated with acetonitrile. CuBr:dpem (2:1)₂. 2MeCN (E = both P, As) are tetranuclear, derivative of the familiar 'step' structure, while CuCl:dpph (MeCN solvate) and CuBr:dppe (MeCN solvate) yield one-dimensional polymers (i.e., x = 1, 2, 6 for dppx, x = m, e, h), as also does CuSCN:dpam (MeCN solvate). In CuI:dpsm:MeCN (3:1:2) ('dpsm' = Ph₂Sb(CH₂)SbPh₂), CuI:dpsm (2:1)₂ 'step' units are connected into an infinite 'stair' polymer by interspersed (MeCN)CuI linkers.

Full text of DOI:10.1016/j.ica.2005.12.019

Inorganica Chimica Acta 359 (2006) 2159–2169
www.elsevier.com/locate/ica
The structural definition of some novel adducts of stoichiometry
CuX:dpex:MeCN (2:1:1)(n), X = (pseudo-) halogen,
dppx = Ph2E(CH2)xEPh2, E = P, As, Sb
a
b
a,
*
Corrado Di Nicola , George A. Koutsantonis , Claudio Pettinari
,
b
b
b
Brian W. Skelton , Neil Somers , Allan H. White
a
`
Dipartimento di Scienze Chimiche, Universita degli Studi di Camerino, via S. Agostino 1, 62032 Camerino MC, Italy
Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley, W.A. 6009, Australia
b
Received 3 November 2005; accepted 11 December 2005
Available online 26 January 2006
Abstract
Single-crystal X-ray studies have defined the structures of a number of novel adducts of the form CuX:dpex (2:1), X = (pseudo)halide,
dpex = bis(diphenylpnicogeno)alkane, Ph2E(CH2)xEPh2, E = P, As, of diverse types, solvated with acetonitrile. CuBr:dpem (2:1)2.
2MeCN (E = both P, As) are tetranuclear, derivative of the familiar ‘step’ structure, while CuCl:dpph (MeCN solvate) and CuBr:dppe
(MeCN solvate) yield one-dimensional polymers (i.e., x = 1, 2, 6 for dppx, x = m, e, h), as also does CuSCN:dpam (MeCN solvate). In
CuI:dpsm:MeCN (3:1:2) (‘dpsm’ = Ph2Sb(CH2)SbPh2), CuI:dpsm (2:1)2 ‘step’ units are connected into an infinite ‘stair’ polymer by
interspersed (MeCN)CuI linkers.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Copper; Bis(diphenylpnicogeno)alkanes; Solvate complexes; X-ray
1. Introduction
structures for dppm (x = 1) with CuCl [8,9], Br [10–12], I
[10,11] and AgCl [13]; there are numerous less immediately
relevant examples involving gold(I). Polymeric forms are
also evident in the Cuac:dppe (4:2) [14], Agac:dppm [15]
and AgNO3:dpae [16] adducts, all complexes involving
bridging oxyanion units. Further examples for M = Ag
have been added in a recent study [17].
In this present sequence of papers, we describe a number
of solvated (i.e., with coordinated solvent) adducts we have
encountered, of diminished MX:L stoichiometric ratio,
normally 2:1, here with copper(I) salts, with diverse dpex
ligands, solvated with acetonitrile, yielding a variety of
diverse forms of considerable novelty; an MeCN adduct
of CuI with dpsm (=Ph2SbCH2SbPh2), which, although
of CuI:dpsm:MeCN (3:1:1) stoichiometry, is of a derivative
extended ‘stair polymer’ form, also based on ‘kernels’ of
2:1 stoichiometry.
Previous contributions [1–6] in the present sequence have
described the structural characterization of unsolvated (i.e.,
no coordinated solvent) adducts of stoichiometry MX:dpex
(1:1) [1–5] or (2:3)n [6], M = univalent coinage metal (cop-
per(I), silver(I)), X = simple anion, usually (pseudo-)halide,
or, when possible, oxyanions ClO4, NO3, carboxylate
(spanning a range of basicities), dpex = Ph2E(CH2)xEPh2,
bis(diphenylpnicogeno)-alkane (or, on occasion, bis(diph-
enylphosphino)-ferrocene, ‘dppf’). Adducts of these combi-
nations with the stoichiometry 2:1 are rather rare in the
literature, being manifested by binuclear [M(l-X)2(l-E-
dpex-E0)2M0] (AgO2CPh:dppf) [7], and tetranuclear ‘step’
*
Corresponding author. Tel.: +39 0737 402234; fax: +39 0737 637345.
E-mail address: claudio.pettinari@unicam.it (C. Pettinari).
0020-1693/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2005.12.019

2160
C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
2. Experimental
2.1. Syntheses
12 h and then filtered. The colorless micro-crystalline pre-
cipitate was washed with acetonitrile to give complex 3 in
50% yield; m.p. 215–220 ꢁC. It is insoluble in most common
organic solvents, a few substantial crystals being obtained
from the mother liquor on standing. IR (nujol, cmꢀ1):
3042w (CHarom), 2290w, 2263w (CN), 1586w, 1569w
(Cꢁ ꢁ ꢁC), 552w, 514w, 484w, 216w, 203w. Anal. Calc. for
C30H30Br2Cu2N2P2: C, 46.95; H, 3.94; N, 3.65. Found:
C, 47.03; H, 4.07; N, 3.53%.
All syntheses and handling were carried out under nitro-
gen under Schlenk conditions. ‘dpsm’ was prepared accord-
ing to the literature [18,19]. All other chemicals were
purchased from Aldrich and Lancaster and used without
further purification. Elemental analyses (C, H, N) were per-
formed in-house with a Fisons Instruments 1108 CHNS-O
Elemental Analyser. IR spectra were recorded from 4000
to 100 cmꢀ1 with a Perkin–Elmer System 2000 FT-IR instru-
ment. 1H and 31P NMR spectra were recorded on a Mercury
2.1.4. CuCl:dpph:MeCN (2:1:1)(1|1) (4)
dpph (0.454 g, 1.0 mmol) was added at room tempera-
ture to an acetonitrile solution (20 ml) of CuCl (0.298 g,
3.0 mmol). After the addition, the solution was stirred for
6 h and then filtered. The colorless micro-crystalline precip-
itate was washed with acetonitrile to give complex 4 in 63%
yield; m.p. 200 ꢁC. It is insoluble in most common organic
solvents, a few substantial crystals being obtained from the
mother liquor on standing. IR (nujol, cmꢀ1): 3042w
(CHarom), 2294w, 2262w (CN), 1613w, 1583w, 1567w
(Cꢁ ꢁ ꢁC), 548br, 519s, 484m, 426w, 441w, 423w, 176w. Anal.
Calc. for C54H50Br2Cu4N2P4: C, 55.41; H, 5.09; N, 2.02.
Found: C, 55.34; H, 5.03; N, 2.19%.
1
Plus Varian 400 NMR spectrometer (400 MHz for H and
162.1 MHz for 31P). H chemical shifts are reported in ppm
versus SiMe4, P chemical shifts in ppm versus H3PO4 85%.
2.1.1. CuBr:dppm:MeCN (2:1:1)2 (1)
dppm (0.576 g, 1.5 mmol) was added at room tempera-
ture to an acetonitrile solution (20 ml) of CuBr (0.572 g,
4.0 mmol). After the addition, the solution was stirred for
48 h and then filtered. The colorless micro-crystalline pre-
cipitate was washed with acetonitrile to give complex 1 in
43% yield; m.p. 300–308 ꢁC; a few crystals suitable for the
X-ray work were obtained from the mother liquor on pro-
2.1.5. CuSCN:dpam (2:1)(1|1) (5)
1
longed standing. H NMR (CDCl3, 293 K): d 2.10 (s, 6H,
dpam (0.472 g, 1.0 mmol) was added at room tempera-
ture to an acetonitrile solution (20 ml) of CuSCN
(0.482 g, 4.0 mmol). After the addition, the solution was
stirred for 24 h and then filtered. The colorless micro-crys-
talline precipitate was washed with acetonitrile to give
complex 4 in 85% yield; m.p. > 300 ꢁC; a few crystals suit-
able for the X-ray work were obtained from the mother
CH3MeCN) 3.45 (s, 4H, PCH2P), 7.0t, 7.14m, 7.28m,
7.30m, 7.58br (40H, C6H5). 31P{1H} NMR (CDCl3,
293 K): d ꢀ13.8 (s br). IR (nujol, cmꢀ1): 3052w (CHarom),
2292w, 2263w (CN), 1583w, 1570w (Cꢁ ꢁ ꢁC), 523m, 510m,
472m, 444w, 432w, 421w, 373w, 355w, 235w, 203w, 177w,
157w. ESI MS (+): 975 [20] [Cu2Br(dppm)2]+; 1117 [10]
1118 [15] [Cu3Br2(dppm)2]+; 1263 [30] [Cu4Br3(dppm)2]+;
1503 [100] [Cu3Br2(dppm)3]+. Anal. Calc. for C54H50Br2-
Cu4N2P4: C, 51.28; H, 3.98; N, 2.21. Found: C, 51.34; H,
4.05; N, 2.18%.
1
liquor on prolonged standing. H NMR (CDCl3, 293 K):
d 3.3 (br, 2H, AsCH2As), 6.9–7.3br (20H, C6H5). IR (nujol,
cmꢀ1): 3045w (CHarom), 2290w, 2265w (CN), 2135m,
2084m (SCN) 1580w, 1570w (Cꢁ ꢁ ꢁC), 585m, 552m, 328m,
312m, 267w, 177s br, 159s br, 123m, 100w, 73w. Anal. Calc.
for C27H22As2Cu2N2S2: C, 45.32; H, 3.10; N, 3.91; S, 8.96.
Found: C, 45.53; H, 3.25; N, 3.97; S, 9.03%.
2.1.2. CuBr:dpam:MeCN (2:1:1)2 (2)
dpam (0.472 g, 1.0 mmol) was added at room tempera-
ture to an acetonitrile solution (20 ml) of CuBr (0.572 g,
4.0 mmol). After the addition, the solution was stirred for
24 h and then filtered. The colorless micro-crystalline pre-
cipitate was washed with acetonitrile to give complex 2 in
63% yield; m.p. > 300 ꢁC; again a few more substantial
crystals were obtained from the mother liquor on standing.
1H NMR (CDCl3, 293 K): d 2.10 (s, 6H, CH3MeCN), 3.3br
(s, 4H, AsCH2As), 6.9–7.6br (40H, C6H5). IR (nujol,
cmꢀ1): 3045w (CHarom), 2291w, 2262w (CN), 1580w,
1570w (Cꢁ ꢁ ꢁC), 585m, 552m, 328m, 312m, 267w, 177s br,
159s br, 123m, 100w, 73w. Anal. Calc. for C54H50As4Br2-
Cu4N2: C, 45.02; H, 3.50; N, 1.94. Found: C, 45.31; H,
3.65; N, 1.97%.
2.1.6. CuI:dpsm:MeCN (3:1:2) (6)
A few crystals of the colorless complex 6 were obtained
by slow evaporation of a solution of millimolar stoichiom-
etries (1:1) of copper iodide and dpsm in acetonitrile.
2.2. Structure determinations
For some of the earlier determinations, unique single
counter diffractometer data sets were measured (2h/h scan
mode; T ca. 295 K; monochromatic Mo Ka radiation,
˚
k = 0.71073 A), Gaussian absorption corrections being
applied, the ‘observed’ criterion being I > 3r(I); for others,
full spheres of CCD area-detector diffractometer data (Bru-
ker AXS instrument, x-scans; T ca. 153 or 300 K) yielded
Nt(otal) reflections, these merging to N unique (Rint cited)
after ‘empirical’/multiscan absorption correction (proprie-
tary software), No with F > 4r(F) considered ‘observed’
2.1.3. CuBr:dppe:MeCN (2:1:2)(1|1) (3)
dppe (0.400 g, 1.0 mmol) was added at room tempera-
ture to an acetonitrile solution (20 ml) of CuCl (0.429 g,
3.0 mmol). After the addition, the solution was stirred for

Table 1
Selected geometries, MX:dppm(:MeCN) (4:2(:2)) (following the nomenclature of Ref. [24])
E/M/X/solvent (phase)
˚
Distances (A)
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
P/Ag/Bra
2.764(2)
2.742(3)
2.721(2)
2.734(2)
2.747(4)
2.735(2)
2.771(2)
2.846(3)
2.554(2)
2.535(2)
2.396(3)
2.402(3)
2.383(3)
2.380(4)
3.650(1)
4.116(2)
3.348(2)
3.346(1)
4.042(2)
3.988(2)
4.232(3)
4.181(3)
3.154(1)
4.019(2)
3.859(2)
3.307(2)
2.905(4)
2.958(2)
3.180(2)
3.108
P/Cu/Cl/(CH2Cl2; C2/c)b
2.312(7)
2.368(3)
2.575(2)
2.785
2.740(5)
2.697(3)
2.579(2)
2.729
2.324(7)
2.358(3)
2.523(2)
2.634
2.357(6)
2.387(3)
2.552(2)
2.711
2.272(5)
2.252(2)
2.338(2)
2.510
2.196(5)
2.203(3)
2.214(4)
2.230
2.194(5)
2.185(3)
2.184(4)
2.216
3.468(5)
3.628(2)
3.449(2)
3.671
3.699(8)
3.548(2)
3.830(2)
4.116
2.914(4)
2.992(2)
2.944(2)
2.684
3.610(7)
3.580(2)
3.832(2)
4.284
3.750(9)
3.723(3)
4.022(2)
4.174
3.494(7)
3.423(2)
3.695(2)
3.349
c
ꢀ
((CH3)2CO; P1)
Br(Pbca)d
I(Pbca)e
P/Cu/Br/MeCNf
(mol. 1)
2.455(1)
2.761(1)
2.638(1)
2.454(1)
2.497(1)
2.527(1)
2.570(1)
2.450(1)
2.473(1)
2.205(2)
2.204(2)
2.216(2)
2.218(2)
3.257(1)
3.104(1)
4.0866(9)
4.0367(8)
3.074(1)
3.090(1)
4.019(1)
3.995(1)
3.814(1)
3.948(1)
3.451(1)
3.597(1)
4.245(1)
4.383(1)
2.167(6)
2.062(5)
(mol. 2)
2.4511(9)
As/Cu/Br/MeCNf
(mol. 1)
2.4561(9)
2.4634(8)
2.6872(9)
2.5619(9)
2.423(1)
2.5144(9)
2.5725(9)
2.4558(9)
2.4632(9)
2.3222(9)
2.3296(8)
2.3382(8)
2.3383(8)
3.137(1)
2.916(1)
4.0802(8)
4.0937(7)
2.930(1)
4.0824(9)
4.0814(8)
3.876(1)
3.662(1)
3.853(1)
4.368(1)
2.030(5)
(mol. 2)
2.4687(9)
2.9833(9)
4.0183(8)
4.6105(8) 2.010(4)
Sb/Cu/I/MeCNf,g
2.6515(6)
2.6830(6)
2.6369(6)
2.6933(6)
2.6402(6)
2.5311(5)
2.5442(6)
2.9800(8)
4.4247(5)
2.8890(7)
4.4731(5)
4.1568(7)
4.260(1)
4.876(1)
Angles (ꢁ)
a
b
c
d
e
f
g
h
i
k
k
l
t
n
s
P/Ag/Bra
97.27(5)
96.29(6)
83.87(5)
82.28(5)
93.69(5)
94.15(5)
74.13(4)
73.84(5)
116.44(8)
115.00(9)
114.17(8)
121.3(1)
69.46(5)
72.53(5)
78.49(5)
78.46(6)
98.67(6)
95.49(6)
144.58(9)
150.6(1)
115.05(9)
109.6(1)
98.67(5)
94.37(5)
97.98(5)
113.9(6)
113.9(6)
1
101.20(6)
P/Cu/Cl/(CH2Cl2; C2/c)b
93.7(2)
88.70(6)
95.98(6)
96.5
88.3(2)
91.30(6)
84.02(6)
83.5
90.6(2)
69.3(1)
71.83(5)
70.03(6)
59.0
129.6(2)
130.79(4)
113.2(1)
112.6
114.8(2)
118.11(6)
116.1(1)
115.9
77.0(2)
76.96(5)
76.68(6)
68.8
78.7(2)
80.90(6)
74.45(6)
62.9
102.5(2)
101.00(5)
103.13(7)
110.1
130.0(2)
136.45(4)
142.5(1)
130.8
127.5(2)
121.98(6)
112.7(1)
109.0
108.0(2)
103.94(6)
104.18(7)
100.7
80.67(8)
88.42(4)
89.20(5)
80.0
110.4(10)
113.44(5)
114.32(6)
113.9
1
ꢀ
b,c
ꢀ
ꢀ
(Me2CO; P1)
89.93(5)
97.36(6)
1
Br(Pbca)d
I(Pbca)e
1
ꢀ
ꢀ
106.0
1
P/Cu/Br/MeCNf
(mol. 1)
ꢀ
102.98(4)
104.93(3)
77.02(8)
75.07(3)
100.66(3)
102.12(3)
70.91(3)
72.77(3)
126.62(6)
120.18(5)
120.62(6)
116.72(6)
87.66(3)
91.50(3)
77.62(4)
76.88(3)
107.69(4)
104.76(3)
119.93(5)
118.71(5)
115.56(6)
114.74(6)
107.69(4)
105.85(3)
82.98(4)
82.42(4)
114.2(3)
116.2(3)
1
ꢀ
(mol. 2)
1
As/Cu/Br/MeCNf
(mol. 1)
ꢀ
104.98(3)
109.09(3)
75.02(3)
70.91(2)
105.84(3)
111.69(3)
68.47(3)
71.05(2)
121.55(4)
111.69(3)
118.30(4)
111.97(4)
94.89(3)
99.82(3)
73.80(3)
74.44(3)
110.35(3)
105.85(3)
115.79(3)
117.55(3)
110.63(3)
108.60(3)
105.18(3)
106.01(3)
75.16(4)
68.42(4)
111.2(2)
113.6(2)
1
ꢀ
(mol. 2)
1
Sb/Cu/I/MeCNf,g
112.09(8)
67.91(2)
114.45(2)
65.02(1)
107.59(2)
116.97(2)
105.69(2)
66.39(1)
113.99(2)
109.04(2)
98.61(2)
103.63(2)
60.15(4)
119.5(2)
1
ꢀ
a M1–X01
b M1–X1
c M1–X2
d M2–X1
e M2–X2
f M1–E1
k X1ꢁ ꢁ ꢁX2
a X1–M1–X01
b M1–X1–M01
c X1–M1–X2
d M1–X1–M2
e E–M1–X01
i X1–M2–X02
k E02–M2–X2
k E02–M2–X1
l X01–M1–X2
(S)
g M02–E2
l X1 ꢁ ꢁ ꢁ X02
m M1 ꢁ ꢁ ꢁ M02
n X1 ꢁ ꢁ ꢁ M02
o M2–S
n E1–M1–X2
e
h M1 ꢁ ꢁ ꢁ M01
i X1 ꢁ ꢁ ꢁ X01
j M1ꢁ ꢁ ꢁM2
g M2–X1–M01
h M1–X2–M2
X
M
2
2
E
c
d
N.B. Nomenclature follows that of Ref. [24]; there is a slight change in the definition
of e, n, l, cf. Ref. [16] t is the M2X2 (central) (obligate planar, if centrosymmetric)/
M2X2 (peripheral) (usually appreciably non-planar) dihedral angle. n is the E–C–E
angle
f
a
b
E
M
1
X
1
1
s is the crystallographic symmetry of the complex
X
M
X
E
E
M
2
g
(S)
a Ref. [13]; b Ref. [7]; c Ref. [8]; d Ref. [12]; note that Ref. [10,11] records a similar (unsolvated) earlier determination in space group P21/c; e Ref. [9] (no s.u.’s available); f this work (1). In the MeCN solvates, N–Cu(2)–Br(10,2), E are:
101.5(2), 96.7(2), 112.3(2) (mol. 1), 114.74(6), 118.71(5), 116.2(2) (mol. 2) (E = P); 105.8(2), 100.9(1), 112.6(1) (mol.1), 101.0(2), 105.7(2), 116.4(1) (mol.2) (E = As). g In the dpsm complex, Cu(3)–I(1,2), I(3) (1 ꢀ x, 1 ꢀ y, ꢀz), N(3)
˚
are 2.6748(6), 2.6218(6), 2.6521(6), 1.989(3) A; N(3)–Cu(3)–I(2,3), I(3) (1 ꢀ x, 1 ꢀ y, ꢀz) are 106.3(1), 111.0(1), 106.5(1)ꢁ; I(2)–Cu(3)–I(3), I(3) (1 ꢀ x, 1 ꢀ y, ꢀz) are 113.28(2), 106.01(2); I(3)–Cu(3)–I(3) (1 ꢀ x, 1 ꢀ y, ꢀz) 113.25(2)ꢁ.
˚
Cu(3)ꢁ ꢁ ꢁCu(2), Cu(3) (1 ꢀ x, 1 ꢀ y, ꢀz) are 2.8968(8), 2.9011(7), I(3)ꢁ ꢁ ꢁI(2,3) (1 ꢀ x, 1 ꢀ y, ꢀz), I(1) 4.2546(7), 4.4044(5), 4.1979(7) A.
The dihedral angle between the Cu(1,2)I(1,2) plane and the Cu(2,3)I(2,3) plane is 63.82(4)ꢁ, while that between the latter and the Cu(3,30)I(3,30) plane is 58.67(3)ꢁ.

2162
C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
3
˚
and used in the full-matrix least-squares refinement, refining
anisotropic displacement parameter forms for the non-
b = 107.435(2)ꢁ, V = 3005 A . Dcalc (Z = 4 f.u.) =
1.672 g cmꢀ3 Mo = 38 cmꢀ1
.
l
;
specimen: 0.20 · 0.20 ·
hydrogen atoms, (x,y,z,Uiso H
)
being constrained at esti-
0.08 mm; ‘T’min/max = 0.49. 2hmax = 58ꢁ; Nt = 33362, N =
7634 (Rint = 0.078), No = 4338; R = 0.045, Rw = 0.045.
mated values unless otherwise noted. Conventional residu-
als R, Rw (weights: (r2(F) + 0.0004F2)ꢀ1) are cited on |F|
at convergence. Neutral atom complex scattering factors
were employed within the XTAL 3.7 program system [20].
Pertinent results are presented in the tables and figures,
the latter showing 20 (room-temperature) or 50% (153 K)
probability amplitude displacement envelopes for the non-
hydrogen atoms, hydrogen atoms having arbitrary radii of
|Dqmax| = 1.6(3) e Aꢀ3. CCD instrument, T ca. 300 K.
˚
CuI:dpsm:MeCN (3:1:2)(1|1) (6) ” C29H28Cu3I3N2Sb2,
M = 1219.4. Triclinic, space group P1, a = 11.435(2) A,
ꢀ
˚
˚
˚
b = 12.485(2) A,
b = 81.396(2)ꢁ, c = 89.975(2)ꢁ, V = 1724 A . Dcalc (Z = 2
f.u.) = 2.349 g cmꢀ3 Mo = 60 cmꢀ1
specimen: 0.32 ·
c = 12.599(2) A,
a = 75.900(2)ꢁ,
3
˚
.
l
;
0.20 · 0.17 mm; ‘T’min/max = 0.70. 2hmax = 58ꢁ; Nt =
˚
0.1 A. Variations in procedure, difficulties, etc., are noted
16642, N = 8257 (Rint = 0.022), No = 7284; R = 0.026,
Rw = 0.034. |Dqmax| = 1.3(1) e Aꢀ3. (x,y,z, Uiso H
)
refined.
˚
as ‘variata’. Full .cif depositions (excluding structure factor
amplitudes) have been deposited with the Cambridge Crys-
tallographic Data Centre, CCDC 244596, 286765–286769.
CuBr:dpem:MeCN (2:1:1)2 ” C58H56E4Br4Cu4N4, E =
CCD instrument, T ca. 153 K.
3. Results and discussion
1
ꢀ
P, As (1, 2). Triclinic, space group P1 (Ci , No. 2), Z = 2
tetramers.
3.1. Syntheses
˚
˚
E = P, M = 1506.8. a = 21.846(3) A, b = 12.085(2) A,
˚
c = 11.943(2) A, a = 82.04(2)ꢁ, b = 80.19(1)ꢁ, c = 84.20(1)ꢁ,
The reaction of two or more equivalents of CuBr with
one equivalent of bis(diphenylphosphino)methane (dppm),
bis(diphenylarsino)methane (dpam), or 1,2-bis(diphenyl-
phosphino)ethane (dppe) at room temperature in acetoni-
trile gave rise to compounds CuBr:dppm:MeCN (2:1:1)2
(1), CuBr:dpam:MeCN (2:1:1)2 (2), and CuBr:dppe:MeCN
(2:1:2)(1|1) (3), respectively. CuCl:dpph:MeCN (2:1:1)(1|1)
V = 3067 A . Dcalc (Z = 4 tetramers) = 1.631 g cmꢀ3
.
3
˚
l
Mo = 41 cmꢀ1; specimen: 0.7 · 0.20 · 0.14 mm; Tmin,max
=
=
0.43, 0.59. 2hmax = 50ꢁ; Nt = 21584, N = 10795 (Rint
0.029), No = 7600; R = 0.043, Rw = 0.050. |Dqmax| = 1.38(8)
e Aꢀ3. Single-counter instrument, T ca. 295 K.
˚
˚
˚
E = As, M = 1682.6. a = 21.892(3) A, b = 12.079(2) A,
c = 11.990(2) A,
˚
a = 81.961(2)ꢁ,
b = 80.581(2)ꢁ,
(4)
(dpph = 1,6-bis(diphenylphosphino)hexane)
and
3
˚
c = 84.164(2)ꢁ, V = 3091 A . Dcalc (Z = 2 tetramers) =
CuSCN:dpam:MeCN (2:1:1)(1|1) (5) were synthesized
from the same solvent by using the same procedure. Small
crystals of the complex CuI:dpsm:MeCN (3:1:2) (6) in low
yields were obtained by slow evaporation of a solution of
1.808 g cmꢀ3
.
l
Mo = 61 cmꢀ1
;
specimen: 0.45 · 0.40 ·
0.35 mm; ‘T’min/max = 0.43. 2hmax = 58ꢁ; Nt = 29505, N =
14461 (Rint = 0.051), No = 11754; R = 0.044, Rw = 0.054.
|Dqmax| = 1.7(2) e Aꢀ3. CCD instrument, T ca. 153 K.
˚
CuBr:dppe:MeCN (2:1:2)(1|1) (3) ” C30H30Br2Cu2N2P2,
M = 767.4. Monoclinic, space group C2/c (C62h, No. 15),
˚
˚
˚
a = 14.303(3) A, b = 11.268(2) A, c = 20.260(4) A, b =
103.37(3)ꢁ, V = 3177 A . Dcalc (Z = 4 f.u.) = 1.605 g cmꢀ3
.
3
˚
1212
1226
l
Mo = 40 cmꢀ1
;
specimen:
0.22 · 0.20 · 0.11 mm;
‘T’min/max = 0.72. 2hmax = 58ꢁ; Nt = 18385, N = 4019
(Rint = 0.041), No = 2918; R = 0.035, Rw = 0.039. |Dqmax| =
1211
1
1121
1221
1111
1122
1.1(1) e Aꢀ3. CCD instrument, T ca. 300 K.
˚
As(12)
As(11)
1112
CuCl:dpph:MeCN (2:1:1)(1|1) (4) ” C32H35Cl2Cu2NP2,
M = 693.6. Monoclinic, space group P21/c, a =
1222
Cu(11)
˚
˚
˚
21.595(5) A, b = 17.045(4) A, c = 17.541(4) A, b =
3
95.155(4)ꢁ, V = 6430 A . Dcalc (Z = 8) = 1.433 g cmꢀ3
.
Br(12)
13
˚
12
Mo = 16.1 cmꢀ1
;
specimen:
0.20 · 0.13 · 0.10 mm;
Br(11)
l
N(12)
‘T’min/max = 0.62. 2hmax = 58ꢁ; Nt = 76153, N = 16537
(Rint = 0.12), No = 9248; R = 0.058, Rw = 0.063. |Dqmax| =
Cu(12)
1.5(3) e Aꢀ3. CCD instrument, T ca. 153 K.
˚
Variata. The copper atoms were modelled as disordered
over pairs of sites, seemingly concerted, occupancies refin-
ing to 0.928(2) and complement. Cuꢁ ꢁ ꢁCu distances are
˚
0.67(3), 0.74(3) (strand 1), 0.81(2), 0.87(2) A (strand 2).
Concomitant minor halide components were not resolved,
nor any involving lighter atoms.
CuSCN:dpam:MeCN (2:1:1)(1|1) (5) ” C29H25N3As2-
Cu2S2, M = 756.6. Monoclinic, space group P21/c,
Fig. 1. Projection of tetranuclear CuBr:dpam:MeCN (4:2:2) (2) ((centro-
symmetric) tetramer 1; tetramer 2 is similar); the E = P counterpart (1) is
isomorphous.
˚
˚
˚
a = 16.842(1) A,
b = 9.5845(8) A,
c = 19.509(2) A,

C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
2163
millimolar stoichiometries (1:1) of copper iodide and
bis(diphenylstibino)methane (dpsm) in acetonitrile.
being 1.0 and 2.2 Xꢀ1 cm2 molꢀ1, respectively. The other
compounds were too insoluble to yield useful data.
The choice of solvent and the ligand to metal ratio are
both determinants in the formation of the compounds,
which, despite their solvation, are generally rather insolu-
ble; they may be representative of more extensive arrays
which present usually as deposits and may be polymers
or polymeric mixtures, even less susceptible of structural
characterization than the present. Normally when both
reactants were mixed and stirred in a 1:1 ligand to metal
molar ratio the well-known 1:1 adducts are obtained. Com-
pounds 1 and 2 are soluble in acetonitrile and DMSO, and
insoluble in alcohols and diethyl ether; they are moderately
soluble also in chlorinated solvents. Conductivity measure-
ments, as expected, indicated that complexes 1 and 2 are
non-electrolytes not only in MeCN but also in dichloro-
methane solution, the values of KM for these compounds
3.2. Spectroscopy
The infrared spectra of 1–5 (see Section 2) are consistent
with the formulations proposed, showing all of the bands
required by the presence of the bis(diphenyl pnico-
geno)alkane donors [21]. The bands due to the P/As/Sb
ligands are only slightly shifted with respect to those of
the free donors. In the far-IR spectra of derivatives 1–4
we assigned, on the basis of a previous report on phos-
phino silver(I) derivatives [22], the broad absorptions near
500 cmꢀ1 and those at 450–400 cmꢀ1 to Whiffen’s y and t
vibrations, respectively. No bands assignable to terminal
Cu–Cl and Cu–Br stretching vibrations have been found.
On the other hand, two broad bands at ca. 160 and
(a)
P
Br
Cu
a
c
(b)
22
21
11
12
P
1
Cu
Br
N(31)
32
33
Fig. 2. Projections of CuBr:dppe:MeCN (2:1:1)(1|1) (3): (a) the unit cell down b, showing the disposition of the polymer strands relative to associated
inversion centres in space group C2/c; (b) a single strand of the polymer.

2164
C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
180 cmꢀ1 have been detected in the spectrum of 1. Analo-
gous bands have been previously assigned to m(Cu–Cl) in
complexes containing a bridging halide group [28].
The positive electrospray mass spectra of complexes 1
and 2 (the most relevant data are reported in Section 2) indi-
cate that these derivatives persist as tetranuclear species also
in a solution. The isotopic distribution of these species is in
accord with the calculated composition. However, the
major peaks are those derived from a trinuclear species con-
taining a 1:1 ligand to metal ratio, positively charged conse-
quent upon loss of a bromide group; no adducts containing
MeCN were detected when the spectra were measured in
acetonitrile. No multiply charged species were observed.
The negative electrospray spectra of 1 and 2 are dominated
by the presence of peaks due to [CuBr2]ꢀ. We have also
studied solutions containing the CuBr and dpem in different
ligand to metal molar ratios. We have observed that peaks
due to [Cu4Br3(dpem)2]+ are present in solution only when a
large excess of the copper bromide (4:1) salt was employed,
whereas when a 1:1 ligand to metal molar ratio was
employed [Cu3Br2(dpem)3]+ is the predominant species.
[Cu2Br(dppm)2]+ and [Cu3Br2(dppm)2]+ were present when
a 1:2 ligand to metal molar ratio was employed, but all
Solution studies, being unlikely to reflect in detail or more
generally the complexed polymeric forms present in the solid,
1
should be considered with that caveat in mind. In the H
NMR spectra of 1, 2 in CD3CN (see Section 2), the signals
due to the diphosphine exhibit a different pattern relative to
those found for the free donors, confirming the occurrence
at least of partial complexation in solution. The bridging
methylene resonances in 1 and 2 appear as broad singlets or
resolved multiplets between 1.00 and 2.50 ppm generally
downfield shifted with respect to those found in the free
1
donors. The H NMR spectra in DMSO of the derivatives
3–5 exhibit the same chemical shift values found in the free
donors, suggesting complete disruption of the polymeric form.
The 31P NMR spectrum (CD3CN solution) of derivative
1 exhibits a broad signal at ꢀ13.8 ppm ascribed to unidenti-
fied fluxional processes. The absorption is downfield shifted
with respect to the corresponding signal in the free ligand.
(a)
(d)
222
221
c
216
P(2)
012
Cl(1)
21
23
12
a
22
13
11
Cu(2)
Cu(1)
Cl(2)
P(1)
112
121
122
P4
Cl3
Cu4
Cu3
Cl4
(b)
422
P1
P(4)
032
Cl2
416
Cl(3)
41
43
42
Cu1
33
Cu(4)
031
Cu(3)
32
Cu2
Cl1
P2
31
Cl(4)
P(3)
312
322
(c)
012
P(1)
032
P(3)
P(3)
P(1)
Cl(4)
031
011
Cu(3’)
N(031)
N(011)
Cu(1’)
Cl(2)
Cu(3)
Cu(1)
N(031)
Cu(3)
Cu(3’)
N(011)
Cu(4’)
Cu(1’)
Cl(1)
Cu(2’)
Cu(4’)
P(4)
Cu(2’)
P(2*)
Cl(3)
Cl(1)
Cl(3)
Cu(4)
012
Cu(2)
032
Cu(4)
Cu(2)
P(2*)
P(4)
Fig. 3. The two strands of the CuCl:dpph:MeCN (2:1:1)(1|1) polymer (4) projected normal to their polymer axes: (a) propagated by the c-glide, and (b) by
inversion centres. (c) The disorder in the binuclear cores. (d) Unit cell contents, projected down b.

C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
2165
peaks, with the exception of that, were due to
[Cu3Br2(dppm)3]+ when an excess of dppm was employed.
the l2-bromines, and on the other equatorial edges by the
dppNH ligands [25], while at a more fundamental level,
one phase of CuCl:dppm (4:2) has very long Mꢁ ꢁ ꢁX dis-
tances within the central M2X2 rhomb [9] (see below).
‘Unsolvated’ MX:dpem (4:2) (X = Cl, Br, I) ‘step’ struc-
tures thus far are predominantly structurally described for
M = Cu, there being only one example for M = Ag (Cl/
dppm), in contrast to the MX:PPh3 (4:4) arrays which,
although not numerous, are described for both M = Cu,
Ag [24]. Interestingly, in these MX:PPh3 adducts, the
peripheral trigonal metal atom (M = Cu or Ag) has an
essentially planar environment (R(angles) = 358.0–359.8ꢁ
for the examples listed in Ref. [24]), a state of affairs carry-
ing over less rigorously to the present: for the unsolvated
examples of Table 1, the sums are 351.4 (P/Ag/Cl),
>358.3 (P/Cu/Cl,Br), 349.9ꢁ (P/Cu/I), suggesting that per-
haps for some of these arrays (those with the largest M
or X?) steric effects due to incorporation of the E x2 into
a chelate may introduce strain. The present work shows the
possibility of solvating these arrays (and their unidentate
3.3. Structural studies
The structures of the present acetonitrile solvated 2:1
adducts of copper(I) salts MX with various L = dpex
ligands have been defined by single-crystal X-ray methods
in a diversity of oligo- and polymeric forms. The oligomers
are, in fact all tetramers, all more or less derivative of the
familiar ‘chair’ or ‘step’ structure, and we discuss them first
in order of increasing complexity.
Archetypical examples of the ‘step’ tetramer have been
described for a considerable variety of M/X (X = Cl, Br,
I) combinations with unidentate group 15 ligands; in this
form central and peripheral pairs of M and X atoms may
be defined. The central M and X atoms are normally
regarded as three-coordinate, leaving the M atom with
the potential to coordinate a fourth unidentate ligand,
while the peripheral M and X are two-coordinate, leaving
the M atom potentially capable of coordinating up to
two further donors. This possibility may be fully realized
in rare MX:L(unidentate) (4:6) adducts, e.g., CuI:2-methyl-
pyridine, the pair of peripheral adducts occupying both
‘axial’ and ‘equatorial’ sites [23]; more usually such adducts
are of 4:4 MX:L stoichiometry, in which case the periphe-
ral substituent is normally ‘axial’, in contrast to the infinite
polymeric ‘stair’ structure where all substituents are ‘equa-
torial’, the ‘axial’ sites being occupied by polymer-extend-
ing linkages. In the simple MX:unidentate L (4:4)
examples of the chair [24], the peripheral metal atoms are
normally three-coordinate, leaving a fourth potential coor-
dination site more or less exposed and thus remaining in
the course of crystallization with excess of coordinating
ligand or solvent, presumably, in the common examples,
because of the relative bulk of the extant substituent vis-
Table 2
Selected geometries, CuCl:dpph:MeCN (2:1:1)(1|1) (4)
Atoms
Parameter
Atoms
Parameter
˚
Distances (A)
Angles (ꢁ)
Cu(1)–Cl(1)–Cu(2)
Cu(1)–Cl(1)
2.392(2),
2.383(2)
2.449(2),
2.438(2)
2.313(2),
2.332(2)
2.278(2),
2.273(2)
2.764(1),
2.742(1)
3.482(2),
3.480(2)
2.201(2),
2.207(2)
2.056(7),
2.085(7)
2.171(2),
2.172(2)
71.95(5), 71.08(5)
71.47(5), 71.10(5)
126.07(7), 126.10(7)
102.1(2), 100.8(2)
116.63(7), 116.76(7)
100.4(2), 100.7(2)
114.8(2), 115.3(2)
92.01(6), 92.42(6)
98.66(6), 98.15(6)
Cu(1)–Cl(2)
Cu(2)–Cl(1)
Cu(2)–Cl(2)
Cu(1)ꢁ ꢁ ꢁCu(2)
Cl(1)ꢁ ꢁ ꢁCl(2)
Cu(1)–P(1)
Cu(1)–N
Cu(1)–Cl(2)–Cu(2)
Cl(1)–Cu(1)–P(1)
Cl(1)–Cu(1)–N
Cl(2)–Cu(1)–P(1)
Cl(2)–Cu(1)–N
`
a-vis any second ligand or coordinating solvent capable
P(1)–Cu(1)–N
of coordinating further. With bidentate dpex, usually
dppm, the ligand usually spans peripheral and central
metal atoms, the archetypical forms being found in the
CuX (X = Cl, Br, I):dppm (4:2) [7–12] and AgCl:dppm
(4:2) [13] adducts; the ligands spanning and coordinating
at central and peripheral sites, as with the unidentate 4:4
complexes, not necessarily pre-empting polymer formation,
but nevertheless presumably hindering it, similarly; as in
the present work, access may certainly be possible in some
circumstances to additional strongly coordinating ligands
of small steric profile, namely acetonitrile. Topologically,
the ‘step’ structure may be regarded as a ‘cube’ structure,
severed along the centre of one face and unfolded; perhaps
unsurprisingly, with relatively minor perturbations in
respect of any or all of M, X, L or, even, lattice forces, it
appears readily susceptible of ‘distortion’ to other confor-
mations. Thus, with the ligand dppNH = P2PNHPPh2,
the 4:2 AgBr adduct takes a form [(l2-Br)(l3-Ag)2(l4-
Br)2(l3-Ag)2(l2-Br)] with an ‘octahedral’ core, the four
equatorial silver atoms spanned pairwise to either side by
Cl(1)–Cu(1)–Cl(2)
Cl(1)–Cu(2)–Cl(2)
Cu(2)–P(2)
Cl(1)–Cu(2)–P(2)
Cl(2)–Cu(2)–P(2)
RCu(2)
128.16(7), 126.94(6)
132.98(6), 134.86(6)
359.8, 360.0
Torsion angles (ꢁ)a
a
b
c
47.1(5),
43.7(5)
a0
b0
c0
ꢀ53.2(5), 58.0(5)
ꢀ177.4(4), 177.4(4)
174.0(5), ꢀ177.1(5)
ꢀ178.5(4),
ꢀ178.2(5)
177.9(5),
ꢀ178.8(5)
ꢀ178.1(5),
180(ꢀ)
d
The two values in each entry are for the major components in polymer
strands 1,2; atoms X(3,4) in the latter are read as X(1,2).
a
Polymer strand 1 is generated by a c-glide; strand 2 is generated by
inversion centres within the two independent ligands to either side of the
Cu2X2 core; thus, all ligands are (quasi-) centrosymmetric.

2166
C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
EPh3 counterparts?) coordinatively, with acetonitrile in the
case of the CuBr/dppm adduct, 1; the dpam counterpart of
the latter, 2, has also been isolated, the first such step tetra-
mer adduct for dpam (E = As). In both of these cases, the
planar three-coordinate array about the peripheral metal
atom is augmented by coordination by the acetonitrile,
which, necessarily, occupies the ‘axial’ site. There are two
independent tetramers in the lattice, both centrosymmetric,
one half of each contributing to the asymmetric unit.
Geometries of the tetramer cores are tabulated compara-
tively with those of their unsolvated congeners in Table
1. In a number of situations, independent equivalent com-
ponents of the same structure are available, showing con-
siderable scatter, presumably consequent on lattice forces.
Nevertheless, on passing from the unsolvated dppm/CuBr
tetramer to the solvated version, the expected trends in
changes in the geometry are found, distances about the
peripheral metal atom generally increasing, while, after
further substitution of dppm by dpam, a weaker donor,
there is a general shortening of the other distances about
the copper atom (see Fig. 1).
The remaining adducts of gross CuX:dpex (2:1) stoichi-
ometry are a diverse array for both X and dpex various, the
majority polymeric with (E-dpex-E0)Cu motifs linked
diversely by anionic motifs to make one- or two-dimen-
sional polymers; the solvent plays a significant role by
increasing metal atom coordination numbers to ‘normal’
(four-coordinate) maximum values.
(a)
N(2)
02
2
01
N(01)
Cu(1)
S(2)
221
Cu(2)
As(2)
211
N(1)
1
222
0
S(1)
As(1)
121
212
112
111
(b)
212
211
111
0
112
As(1)
As(2)
221
122
226
Cu(1)
Cu(2)
S(1)
1
N(01)
01
N(1)
S(2)
02
2
N(2)
Fig. 4. (a) The double-stranded polymer of CuSCN:dpam:MeCN (2:1:1)2(1|1) (5) projected normal to its propagation axis; (b) the fused bicyclic motif.

C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
2167
˚
The adducts CuX:dppx (2:1)(1|1), (a) X = Br, x = e (3),
(b) X = Cl, x = h (4) are similar, in that the Cu(P-dppx-
P0)Cu units are linked by Cu(l-X)2Cu rhombs, whence
the stoichiometry; the coordination number of the metal
in such a ꢁ ꢁ ꢁ-dppx-(P)Cu(l-X)2Cu(P-dppxꢁ ꢁ ꢁ) array being
three, and both adducts being crystallized from acetoni-
trile, it is unsurprising to find the coordination numbers
of the copper atoms augmented by acetonitrile coordina-
tion. Interestingly, however, we find the extent to which
this occurs to differ between the two compounds, all copper
atoms accepting fourth/acetonitrile donors in the
CuBr:dppe adduct, but only one of each pair in the dpph
adduct, which, moreover, contains a pair of independent
strands with different internal symmetries.
lengthening to 2.72(3), 2.89(2) A. These distances associ-
ated with the disordered components are inherently impre-
cise and moreover, may be presumed to be associated with
some degree of repositioning or reorientation of the chlo-
rine and acetonitrile moieties, the minor fragments of these
being unresolved. Values and trends in bond lengths and
angles for the two copper types are essentially as expected.
A consequence of the different symmetry generators of the
two strands is that in strand 1 the ligand string is ht ht ht
with the acetonitrile/-coordinated copper consistently asso-
ciated with coordination of the one phosphorus atom,
while in strand 2, the sequence is hh h0h0 hh h0h0 so that
the two phosphorus atoms of one ligand are associated
with the same type of copper atom. Both Cu2Cl2 arrays
are markedly non-planar, the ‘folds’ at the Clꢁ ꢁ ꢁCl lines
being 48.36(8)ꢁ, 49.45(8)ꢁ; the agency of the fold is
obscure, perhaps a consequence of ‘lattice forces’, since
the packing of the array in the cell is impressive
(Fig. 3) – the possibility that it may originate in ‘crevice’
coordination of the acetonitrile between both copper
atoms is considered and discarded, the other Cuꢁ ꢁ ꢁN
In CuBr:dppe:MeCN (2:1:1)(1|1) (3), one half of that
formula unit, i.e., CuBr:0.5 dppe, comprises the asymmet-
ric unit of the structure, a crystallographic inversion centre
lying at the centre of the dppe ligand, the torsion in the cen-
tral bond being obligate 180ꢁ/anti, with further inversion
centres at the centres of the Cu(l-Br)2Cu rhombs, which
are obligate planar (Fig. 2). Cu–Br, Br0 are somewhat
0
˚
˚
unsymmetrical (2.5890(6), 2.4774(7) A), with Cu–Br–Cu
distances being 3.102(6), 3.046(7) A, with a closely pla-
73.94(2)ꢁ; Br–Cu–Br0 106.06(2)ꢁ. Cu–N,P are 2.038(4),
2.232(1) with N–Cu–P 113.9(1)ꢁ; N–Cu–Br, Br0 are
101.83(9), 103.91(9) and P–Cu–Br, Br0 110.17(3)ꢁ,
119.25(3)ꢁ, and torsion Cu–P–C(1)–C(10) ꢀ47.7(3)ꢁ.
nar copper environment, although there is a precedent
with pyridine and [cy3PAgI2AgPcy3], associated with
considerable folding of the AgI2Ag array [26] (see
Table 2).
The CuSCN:dpam (2:1) adduct, also solvated by aceto-
nitrile and also polymeric, CuSCN:dpam:MeCN
(2:1:1)2(1|1) (5) (Fig. 4 and Table 3) is more complex
and interesting. The polymer is double-stranded, propa-
gated up the centre of a P21/c unit cell, by inversion and
The single-stranded polymer form is also found in
CuCl:dpph (2:1) as crystallized from acetonitrile as a
monosolvate (4); two independent strands are found, both
similar in aspect, the first propagated by the c-glide, the
second by inversion centres. This structure is remarkable
in a number of aspects. The form of the polymer is that
of familiar M(l-X)2M units linked this time by one, rather
than two (as in Ref. [4]) dppx ligands, demanding, at least
incipiently, three- rather than four-coordinate metal atoms;
there are two independent pseudo-symmetrically related
polymer strands. Within each of the independent Cu2Cl2
cores, one of the copper atoms is indeed, three-coordinate;
the coordination number of the other is increased to four
by coordination of the acetonitrile solvent molecule. While
M2Cl2 (M2X2) rhombs of the present type are known for a
variety of forms: EM(l-X)2ME, EM(l-X)2ME2, E2M(l-
X)2ME2, EE0M(l-X)2MEE0, E = N, P,. . ., we are not
aware of any hitherto defined of the form EM(l-X)2MEE0.
Disorder is noted in the copper atoms, consistent across all
four, raising the query as to whether there may be a minor
component of cocrystallized polymer devoid of MeCN or
with different MeCN coordination (for example). We
believe it may be understood rationally in terms of
interchange between the possibilities of three- and four-
coordinate sites: the small component adjacent to the
three-coordinate (planar environment) copper(I) atom lies
out of that plane and towards the acetonitrile, so that
Table 3
Selected geometries, CuSCN:dpam:MeCN (2:1:1)(1|1) (5)
Atoms
Parameter
Atoms
Parameter
˚
Distances (A)
Cu(1)–As(1)
Cu(1)–S(1)
Cu(1)–S(2)
Cu(1)–N(01)
S(1)–C(1)
2.364(1)
2.401(2)
2.423(1)
1.966(5)
1.654(6)
1.152(7)
Cu(2)–As(2)
Cu(2)–S(2)
Cu(2)–N(1i)
Cu(2)–N(2ii)
S(2)–C(2)
2.379(1)
2.516(2)
1.966(5)
1.978(6)
1.649(7)
1.173(9)
C(1)–N(1)
C(2)–N(2)
Angles (ꢁ)
As(1)–Cu(1)–S(1)
As(1)–Cu(1)–S(2)
As(1)–Cu(1)–N(01)
N(01)–Cu(1)–S(1)
N(01)–Cu(1)–S(2)
S(1)–Cu(1)–S(2)
Cu(1)–S(1)–C(1)
S(1)–C(1)–N(1)
C(1)–N(1)–Cu(2i)
Cu(1)–N(01)–C(01)
As(1)–C(0)–As(2)
107.40(6)
102.13(5)
126.1(2)
105.5(2)
104.2(2)
111.00(7)
103.3(2)
178.0(7)
170.9(5)
167.6(6)
112.9(3)
As(2)–Cu(2)–S(2)
As(2)–Cu(2)–N(1iii)
As(2)–Cu(2)–N(2ii)
S(2)–Cu(2)–N(1iii)
S(2)–Cu(2)–N(2ii)
N(1i)–Cu(2)–N(2iii)
Cu(2)–S(2)–C(2)
S(2)–C(2)–N(2)
C(2)–N(2)–Cu(2ii)
Cu(1)–S(2)–C(2)
Cu(1)–S(2)–Cu(2)
101.17(5)
113.0(2)
112.3(2)
115.4(2)
99.6(2)
114.1(2)
98.8(2)
178.3(5)
159.7(5)
99.1(2)
114.75(7)
Transformations of the asymmetric unit: (i) x, 1 + y, z; (ii) 1 ꢀ x, 1 ꢀ y,
1 ꢀ z; (iii) x, 1 ꢀ y, z.
˚
Cuꢁ ꢁ ꢁN 3.102(6), 3.046(7) A, become supplanted by
0
˚
Cu ꢁ ꢁ ꢁN 2.40(3), 2.21(2) A in the disordered form, while
the disordered components of the four-coordinate Cu
retreat towards a planar PCl2 environment, with Cu0ꢁ ꢁ ꢁN
In the ring Cu(1)As(1)C(0)As(2)Cu(2)S(2), torsions in the bonds succes-
sively are ꢀ53.3(2)ꢁ, 5.1(4)ꢁ, 59.4(3)ꢁ, ꢀ59.2(2)ꢁ, 1.22(7)ꢁ, 42.53(7)ꢁ, i.e., a
‘boat’ with Cu(1), As(2) at the prows.

2168
C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
(a)
112
122
121
211
212
0
31
3
Sb(2)
Sb(1)
222
N(3)
I(1)
Cu(1)
I(3)
Cu(3)
Cu(2)
I(2)
(b)
I(3)
I(1)
Cu(2)
Cu(3)
Cu(1)
Sb(1)
0
I(2)
212
N(3)
3
111
Sb(2)
41
211
31
12
N(4)
122
bSin
222
cSin
Fig. 5. Two views of the polymer of CuI:dpsm:MeCN (3:1:1)(1|1) (6): (a) projected down b* and (b) within the unit cell, projected down a.
b translation. About (1/2,y,1/2), the two strands are linked
The coordination environment of Cu(1) is completed by
(terminal) acetonitrile and the sulfur of (translation-
related) thiocyanate 1, propagating the polymer along b.
S(1) is coordinated to one copper atom only, S(2) bifurcat-
ing a pair, one of each type, all with similar C–S–Cu angles
(Table 3).
Although not of 2:1 MX:dpex stoichiometry, nor of
any of the above forms, it is appropriate to record here
the only dpsm (= Sb-dpsm-Sb0) complex we have hitherto
obtained, namely, CuI:dpsm:MeCN (3:1:1(+1))(1|1) (6), a
ꢀ
ꢁ
SCN
NCS
by the familiar eight-membered ring motif Cu
Cu,
disposed about a crystallographic inversion centre and
comprised of {Cu(2)SCN(2)}2 with the two SCN rods obli-
gate parallel. The other two coordination sites about Cu(2)
are made up of As(2) of the dpam ligand and the nitrogen
of thiocyanate 1; As(1) of the dpam ligand bonds to Cu(1),
bridged to Cu(2) by the sulfur of thiocyanate 2, thus creat-
ing a novel fused system of eight- and six-membered rings.

C. Di Nicola et al. / Inorganica Chimica Acta 359 (2006) 2159–2169
2169
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polymer’ motif, well known for adducts of the coinage
metal halides [27] and derivative of the above ‘step’ struc-
ture (Fig. 5 and Table 1); the precautionary form of the
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per formula unit of acetonitrile is coordinated and one
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´
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