Structure of two Tetracyano Complexes with Dien: Ni(dien)2Ni(CN)4
NDNC: the sample of NDNCH crystals were ground in an agate
mortar and heated in an oven at 100°C for one hour. Calc. (Mr ϭ
427.81): C, 33.69; H, 6.13; N, 32.74%. Found : C, 33.75; H, 5.88;
N, 32.33%.
geometric parameters are presented in Table 3, while the possible
hydrogen bonds are gathered in Table 4.
Crystallographic data (excluding structure factors) for the struc-
tures reported in this paper have been deposited with the Cam-
bridge Crystallographic Data Center as supplementary publication
no. CCDC-165239 (NDNCH) and CCDC-165240 (NDPC). Copies
of the data can be obtained free of charge on application to CCDC,
12 Union Road, Cambridge CB2 1EZ, UK [Fax: int. Code
ϩ44(1223)336-033; E-mail: {HYPERLINK mailto:
IR spectroscopy
The IR spectra were measured on a Perkin-Elmer FT-IR instru-
ment. Here are given the important well identifiable absorption
bands:
deposit@ccdc.cam.ac.uk]} deposit@ccdc.cam.ac.uk].
NDNCH: ν(OH): 3642m, 3627wsh, 3565w, 3544wsh; ν(NH2): 3328vs, 3267
vs, 3234vs, 3175 vs, 3155ssh; ν(CH2): 2957s, 2919s, 2876s; ν(CN): 2121vs,
2113vs; δ(OH2): 1693wsh, 1622msh; δ(NH2): 1599m, 1582m; ρ(NH2): 625m,
Results and Discussion
609m; δ(NC-CN): 525m, 514m, 486w; δ(Ni-CN): 412s cmϪ1
.
Using [Ni(dien)2]2ϩ cations and [Ni(CN)4]2Ϫ and
[Pd(CN)4]2Ϫ anions, respectively, as building blocks two
compounds with ionic structures crystallise from the aque-
ous solution. The results of structure analysis of NDNCH
confirmed the identity of the isolated compound with the
previously described one [12]. Its atomic co-ordinates and
geometric parameters were deposited (see above).
NDNC: ν(NH2): 3337vs, 3310vs, 3274vs, 3246ssh, 3175msh; ν(CH2):
2952msh, 2932m, 2877m; ν(CN): 2125ssh, 2117vs; δ(NH2): 1579m; ρ(NH2):
612m; δ(NC-CN): 519m; δ(Ni-CN): 417m cmϪ1
.
NDPC: ν(NH2): 3339vs, 3314vs, 3273vs, 3171msh; ν(CH2): 2973wsh,
2953msh, 2935s, 2879s, 2865s; ν(CN): 2136ssh, 2128vs; δ(NH2): 1581s;
ρ(NH2): 611m; δ(NC-CN): 519m, 484w; δ(Pd-CN): 409m cmϪ1
.
The structure of the new compound NDPC is formed of
[Ni(dien)2]2ϩ cations and [Pd(CN)4]2Ϫ square anions (Fig.
1). The arrangement of the ions in the unit cell corresponds
to the deformed NaCl structure type. Beside strong Cou-
lombic attraction to the packing forces contribute also weak
HBs of the N-H···NC type (Table 4). The cation like in
NDNCH is mer isomer. Same type of cation was found e.g.
Thermal analysis
The thermal behaviour of NDNC was studied on a Derivatograph
OD-102 instrument (MOM Budapest). TG, DTG and DTA curves
were recorded under following experimental conditions: TG ϭ 100
mg, DTG ϭ 1/5, DTA ϭ 1/5, air atmosphere, ceramic crucibles,
heating rate 10°/min, tmax ϭ 1000°C. The final product was exam-
ined by X-ray powder diffraction method using a DRON-2 dif-
fractometer and CuKα radiation.
in
the
trinuclear
molecular
tetracyanonickellate
{[Ni(dien)]2(C2O4)Ni(CN)4} [17]. An s-fac isomer of the
cation was found in the [Ni(dien)2]CA · 2H2O (CA ϭ chlor-
anilate) compound [12].
X-ray crystallography
There exist three pairs of mean Ni-N bond distances, na-
˚
Data for NDNCH and NDPC (data are given in parentheses),
respectively, were collected on a Enraf-Nonius (CAD4) four-circle
diffractometer using graphite monochromated CuKα (MoKα) radi-
mely 2.08, 2.13 and 2.17 A in the NiN6 octahedron in
NDPC (Table 3). The shortest Ni-N distances correspond
to the bonds of the nickel central atom to the secondary
amine group nitrogen atom. The corresponding Ni-N bond
distances in NDPC are almost the same as in NDNCH de-
spite the different temperature of data collection, and at
the same time these values are somewhat shorter than the
corresponding ones found in the previous structure deter-
mination of NDNCH [12]. The bond distances and angles
in the chelate rings exhibit usual values [18]. The confor-
mation of the chelate rings is the same (δλ) as in NDNCH.
The co-ordination of the palladium atom is exactly
˚
˚
ation with λ ϭ 1.54178 A (λ ϭ 0.71073 A). Cell parameters were
refined using 45 (25) reflections. Three control reflections were
measured every two hours during data collection and no intensity
decay was observed. For the crystal of NDNCH mounted in a glass
capillary a numerical absorption correction was made using the
measured crystal faces (the number in the parentheses are the dis-
tances (in mm) of the respective face from an arbitrary centre: 001
¯
¯
¯
¯
(0.025), 001 (0.025), 110 (0.080), 110 (0.080), 100 (0.20), 100 (0.20).
The absorption correction in the case of NDPC was based on ψ-
scans.
¯
planar as required by symmetry (1). All cyano groups are
The structures were solved by the heavy atom methods in
SHELXS86 [13], and refined using full-matrix least squares by
SHELXL97 [14]. The non-H atoms were treated anisotropically.
The O2 atom in NDNCH was disordered, its less populated posi-
tion (O21) was treated isotropically. Hydrogen atoms in NDNCH
were treated riding on calculated positions, hydrogen atoms of the
water molecule in NDNCH were found from a difference map. In
NDNCH only isotropic displacement parameters of the hydrogen
atoms common by groups were refined, while in NDPC also their
positions were refined. Some further details along with the final
values of crystallographic residuals are given in Table 1. Geometric
parameters were calculated by using the program PARST [15] and
the figures were drawn using the program DIAMOND [16]. The
atomic co-ordinates of NDPC are collected in Table 2, selected
terminal, they are linked only by hydrogen bonds to water
molecules or dien ligands. The geometric parameters in
these anions are as usual [5, 19].
The NDNCH compound is very sensitive to handling, it
readily decomposes on air due to dehydration. In the pre-
vious X-ray determination made on 20°C [12] it was noted
that a 20% lost of intensity of the control reflections was
observed during data collection. It seems that the higher
final value of R1 factor was influenced by partial deterior-
ation of the single crystal. With our data, free refinement
of the oxygen site occupation factors gave no indication of
understoichiometry. As expected, our cell parameters of
Z. Anorg. Allg. Chem. 2002, 628, 344Ϫ348
345
Ernak, Juraj
