4383
Crystal and Molecular Structure of the Five-Coordinated Nickel ( 11) Complex with N-~-Diethylaminoethy1-5-chlorosalicylaldimine P. L. Orioli, M. Di Vaira, and L. Sacconi
Contribution f r o m the Istituto di Chimica Generale ed Inorganica, Universiti di Firenze, Florence, Italy. Received April 26, 1966 Abstract: The crystal structure of bis(N-p-diethylaminoethyl-5-chlorosalicylald~m~ato)n~cke~(II) has been determined by X-ray analysis. The cell dimensions are: a = 12.68,b = 21.77, c = 12.05 A, p = 122' 48', 2 = 4, space
group P2,/c. The structure consists of discrete molecules,in which the nickel atom shows the coordination number of five. The coordination polyhedron can be described as a distorted square pyramid formed by the two oxygen atoms, the two azomethine nitrogen atoms, and the &nitrogen atom of one ethylenediamine group. Sixfold coordination appears to be essentially prevented by steric hindrance of the two ethyl groups. The steric requirements of the ligand molecule are the main factors determining the distribution of the ligands about the metal atom. This is the first complete structure of a high-spin five-coordinated nickel(I1) complex. chiff bases formed by the reaction between ringsubstituted salicylaldehydes and N,N-diethylethylenediamine give complexes with nickel(I1) of the general formula [X-SALen-N(C2Hs)2]2Ni. Paramagnetic octahedral or diamagnetic planar complexes are formed depending on the nature of the X substituent in the benzene ring. When X = 3-C1, 5-C1, or 3,4-benzo, paramagnetic complexes are formed whose reflectance spectra are not readily assigned on the basis of either octahedral or tetrahedral forms. In a previous communication2 we reported preliminary results on the structure of the 5-C1 derivative and have shown the cobalt(I1) analog to be isomorphous with the nickel complex. We wish now to report the complete results of the three-dimensional X-ray investigation on this compound.
S
Experimental Section The preparation of the compound has been described elsewhere. Monoclinic needles were grown from chloroform and petroleum ether (bp 40-70") solutions, the axis of elongation being [Ool]. Cell dimensions, determined from rotation and Weissenberg photographs,are: a = 12.68,b= 2 1 . 7 7 , ~= 12.05A,P=l22"48',2= 4, calculated density 1.32 g ~ m - ~The . NaCl rotation pattern was superimposed on each film for calibration. Systematic absences of (h00 for I odd and (OkO) for k odd indicated the space group to be PZ,/c. The crystals, perfectly stable in the air, slowly transform under exposure to X-rays into a brown diamagnetic powder. Analysis of the powder shows that decomposition takes place. Owing to the decomposition, four different crystals, of about the same size, were employed for the collection of the intensities. Data were collected around the needle axis on a Nonius integrating Weissenberg camera with nickel-filtered Cu Ka radiation (1.5418 A). hkO through hk9 reciprocal lattice levels were collected using the multiple-film equiinclination technique. The various levels were scaled by means of two special integrated Weissenberg photographs, containing 30" samples from each layer. The appearance of the photographs was very poor. The intensities of the reflections fell off rapidly with sin 0 and no reflection could be observed beyond sin O j X = 0.45, even with high-exposure times. All the photographs showed a fairly intense background. Nevertheless, 1968 reflections were examined, but 478 were found too weak to be measured. The intensities of the integrated diffraction spots were measured on a Nonius microdensitometer, (1) L. Sacconi, P. Nannelli, N. Nardi, and U. Campigli, Inorg. Chem.,
4, 943 (1965).
(2) L. Sacconi, P. L. Orioli, and M. Di Vaira, J . A m . Chem. SOC.,87, 2059 (1965).
Orioli, Di Vaira, Sacconi
the density being assumed proportional to the intensity of the reflections. Intensities were corrected for Lorentz and polarization factors. No correction was applied for absorption and for anomalolls dispersion. The reflection j02 was later considered to be affected by secondary extinction and omitted from the least-squares refinement and from the calculation of the final R factor. The atomic scattering factors used were those of Viervoll and for chlorine, oxygen, @grim3for nickel, those of Berghuis, et nitrogen, and carbon, and those of McWeeny5for hydrogen.
Determinationof the Structure From a three-dimensional Patterson synthesis the nickel atoms were easily located. A Fourier synthesis, calculated with the contribution of the nickel atoms only, showed more or less clearly all the atoms of the salicylaldimine residues. Interpretation of the Fourier synthesis was made with the aid of a model. Two successive Fourier and one AF synthesis gave the positions of all 35 nonhydrogen atoms. The location of the carbon atoms of the ethyl groups attached to N S (Figure 1) presented some difficulties, owing to the poor resolution of the electron density peaks. Geometrical considerations were also employed for the location of these atoms. At this point the conventional R factor was 30.0%. This rather high value was due mainly to the difficulty of guessing proper temperature factors for the atoms, in a structure where thermal motion seems to be quite important. R is throughout defined as 2i/Fo1 - 1 Fcl(/ Z 1 FoI, where the sums are over the independent, observed reflections. Refinement was continued by means of block diagonal least squares, with individual isotropic temperature factors. Only the observed reflections were introduced in the least-squares calculations. The function minimized was 2wllFo[ - /Fc1/2. Weights were assigned according to the function : w = l/(a F, cFO2)with a 'v 2 Fminand c II 2/FmaxS6 Convergence proceeded slowly and after several cycles it was decided to try full-matrix least-squares
+ +
(3) H. Viervoll and 0. @grim, Acta Cryst., 2, 277 (1949). (4) J. Berghuis, I. M. Haanappel, M. Potters, B. 0. Loopstra, C. H. Mac Gillavry, and A. L. Veenendaal, ibid., 8, 478 (1955). ( 5 ) R. McWeeny, ibid., 4, 513 (1951). (6) D. W. Cruickshank, et al., "Computing Methods and the Phase
Problem in X-ray Crystal Analysis," Pergamon Press, Oxford, 1961.
I Ni(l+N-b-
diethy laminoethyl-5-chlorosalicylaldimine Complex
4384 Table I. Positional Parameters, Temperature Factors, and Their Estimated Standard Deviations Atom
xla
Ni el-1 CI-2 0-1 0-2 N- 1 N-2 N-3 N-4 c-1 c-2 c-3 c-4
0.0566 -0.0217 -0,4099 0.1256 -0.0634 -0.0461 0,0293 -0.3331 0.2363 -0.0623 0.0013 -0.0366 0,0258 0.1201 0.1585 0,0948 -0.1259 -0.2519 -0.3618 -0.3657 -0.4807 -0.4606 -0.051 1 -0.1367 -0.2188 -0.3023 -0.3084 -0.2276 -0.1407 0.1158 0.2503 0.3548 0,3477 0.2374 0.3562
c-5 C- 6
c-I c-8 c-9 c-10 c-11 c-12 C-13 C-14 c-15 C-16 C-17 c-18 C-19 c-20 c-21 c-22 C-23 C-24 c-25 C-26
62
x
106
ylb
31 72 71 129 118 148 154 218 173 186 181 189 191 199 188 194 207 228 305 314 306 302 196 169 193 21 1 216 229 199 238 274 272 253 237 263
by
0.1785 0.0451 0.3776 0.1777 0.2436 0.1051 0.1943 0.0896 0. 1424 0.0803 0.0991 0.0670 0.0810 0.1242 0.1534 0.1448 0.0771 0.1108 0.0294 0.0128 0 1201 0.1829 0.2312 0,2655 0.2993 0.3371 0.3461 0.3128 0.2723 0.1572 0.1626 0.1691 0.2332 0,0767 0,0404
refinement. This new series of cycles was executed at the University of Washington, with the least-squares program of Busing and Levy, adapted for the 7094 by S t e ~ a r t . ~
x
105
16 35 35 67 59 72 73 117 90 93 89 91 94 97 92 97 103 109 168 164 160 159 93 84 91 100 105 112 98 116 134 142 137 123 125
u2 X
zjc
-0.1288 0.3698 -0.6432 0 0585 -0.1625 -0.1544 -0.3058 -0.4990 -0.0879 -0 0667 0,0682 0.1418 0.2744 0.3367 0.2618 0.1271 -0.2938 - 0.3599 - 0.5079 -0.6644 - 0.5599 -0.5779 -0.3985 -0.3854 -0.5014 -0.4954 -0.3903 -0,2716 -0.2727 -0.3258 -0.1936 0.0370 0.0526 - 0.0567 -0,0289
Figure 1. Schematic drawing of the moIecule showing the labeling
The weighting scheme used in this series of cycles 40; d w= was: 4; = 1 for reflections with F~ the shifts in 40/F~for Fo > 40. After two cyc1es the coordinates were less than the standard deviations, but the temperature factors still showed large shifts. The R factor at this point was l5*7%. Convergence for the temperature factors was attained after four more cyc1es, but improved Only the standard deviations of the coordinates increased by CQ. 1.5 times, and a few C-C bond lengths showed
