Structure of bis(ethylenediamine)copper(II) tetracyanonickelate(II)

[Cu(C4HI6N4)][Ni(CN)4], Mr = 346'5, triclinic, P i , a = 6 . 4 6 0 ( 9 ) , b = 7.230(10), c = 7.864 (15)A, a = 106.81 (13), /3 =91"51 (14), y = 106.94 (12) °, V = 333"9 (9) A 3, Z = 1, O m = 1"71 (1), Dx=1"723Mgm -3, A ( M o K a ) = 0 7 1 0 6 9 A , /x= 3"55 m m 1, F(000) = 177, T = 293 K, final R = 0.056 for 1212 unique observed reflections. The structure consists of centrosymmetric [Cu(en)2] 2+ (en = ethylenediamine) cations and [Ni(CN)4] 2anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains running along the [111] direction. Bridging by the CN groups is clearly unsymmetrical [ N i C = 1.850 (4) and C u N = 2.533 (4) ,A,], leading to fourcoordinate Ni n species alternating with axially distorted octahedral Cu II groups along the chain [the equatorial C u N distances are 1.997(3) and 2.001 (3) A]. Experimental. The title compound, (I), was prepared by mixing equimolar amounts of K2Ni(CN)4 and CuSO4.5H20 (dissolved in H20). The resulting precipitate was collected by filtration, washed with H20 and dissolved in ethylenediamine/ethanol. Finally, 4-5 volumes of C6H 6 (or C6D6) were added and allowed to stand until crystals appeared. Crystal size: 1.0 x 0.6 × 0.4 mm, D,,, by flotation in bromoforrn-cyclohexane, Weissenberg photographs consistent with Laue symmetry 1. Syntex P21 diffractometer; unit-cell parameters by least-squares refinement of 22 reflections, 7 < 20 < 26°; intensity data (h = 0 to 8, k = 9 to 8, l = 10 to 9) collected with graphite-monochromated MoKa radiation, 0-20 scan mode, variable scan speed, scan width 2 ° (in 20) plus al a2 dispersion. Two standard reflections measured every 100 reflections, these varied by less than 5%; intensities corrected for Lorentzpolarization effects but not for absorption; 1550 unique reflections, 20 _< 55 °, 1212 with I _ 20"(/) considered observed and included in the refinement. Structure solved by the heavy-atom method using XFPS (Pavel~ik, 1986) and refined by block-diagonal least-squares methods, anisotropic thermal parameters for non-H atoms, H atoms fixed at calculated positions with isotropic thermal parameters set to Beq of the bonded atoms; in final cycle R = 0-056, wR =0.073 for observed reflections only, S = 1.51, (d/0")max = 0"03, function minimized ~w(AF) 2, where w-1 = 0"2(Fo) + (CIFo! )2 [0"(Fo) derived from pulse statistics and C = 0.018, in order to make w(AF) 2 approximately independent of IFol and sinO/A], max. and min. heights in final Ap synthesis 0.86 and -0 . 77 e A -3. Scattering factors for neutral atoms from International Tables for X-ray Crystallography (1974, Vol. IV); all calculations except XFPS performed with local version of NRC (1973). Final atomic coordinates of non-H atoms and equivalent isotropic B's are listed in Table 1,* bond * Lists of structure factors, anisotropic thermal parameters, and H-atom parameters have been deposited with the British Library Document Supply Centre as Supplementary Publication No. SUP 54285 (10 pp.). Copies may be obtained through The Technical Editor, International Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, England. 0108-2701/91/112447-02503.00 © 1991 International Union of Crystallography 2448 BIS(ETHYLENEDIAMINE)COPPER(II) TETRACYANONICKELATE(II) Table 1. Final atomic coordinates ( × 104) and equivalent isotropic thermal parameters (A 2) with e.s. d, s in parentheses B,q = (413)Y.Yfl,ja, aj. x y z Cu(l) 0 0 0 Ni(1) 5000 5000 5000 N(1) -898 (5) -2645 (5) 526 (4) N(2) 1604 (5) 923 (5) 2057 (4) N(3) 3520 (6) 1081 (5) 2048 (5) N(4) 1617 (6) 6152 (6) 3252 (5) C(1) -2698 (7) -2654 (7) 1622 (6) C(2) 2139 (8) 607 (7) 2975 (6) C(3) 4101 (6) 2539 (6) 3188 (5) C(4) 2882 (6) 5754 (6) 3960 (5) Table 2. Bond lengths (,~) and angles (o) with e.s. d. 's in paren theses Cu(1)---N(1) 1.997 (3) Ni(1)---C(3) Cu(1)--N(2) 2.001 (3) Ni(1)---C(4) N(1)---C(1) 1.465 (6) C(3)---N(3) C(1)---C(2) 1.487 (7) C(4)---N(4) C(2)--N(2) 1.455 (6) 1.850 (4) 1.864 (4) 1.123 (5) 1-125 (6) N(1)--C~(1)--N(2) 84.6 (1) N(2)--C(2)--C(1) 108.7 (4) Cu(1)---N(1)--C(1) 107-9 (3) C(3)--Ni(1)--C(4) 88-1 (2) Cu(1)--N(2)--C(2) 108.7 (3) Ni(1)--C(3)--N(3) 177.2 (4) N(1)--C(1)--C(2) 107-3 (4) Yi(1)--C(4)--Y(4) 176.6 (4) distances and angles in Table 2. A stereoview of the structure and the numbering scheme is given in Fig. 1. Related literature. Following the report (Williams, Larson & Cromer, 1972) that the mixed-valence copper cyanide ethylenediamine complex, CuI(CN)4 CuII(en)2.H20 (II), forms a three-dimensional network in the solid state, we attempted to prepare a ~ I 4 ° H ~ H1 H5 . ,,,oH 6 N4'