The x-ray crystallographic structures of (η5-C5H4CHO)Cr(CO)2NO (I), (η5-C5H4CN)Cr(CO)2NO (II), and (η5-C5H4NH2)Cr(CO)2NO (III) are described. The formyl and amino derivatives were obtained from a literature preparation (Macomber and Rausch, 1983). The cyano derivative (II) was obtained by conversion of (η5-C5H4COOH)Cr(CO)2NO into [(η5-C5H4C(O)NH2]Cr(CO)2NO, followed by dehydration of the amide in acetic anhydride. (I) crystallizes in the monoclinic space group P21/n with a=8.028(3), b=11.605(4), c=9.730(3)Å, β=90.04(2)°, and Dcalc=1.69 g cm-3 for Z=4. Refinement led to an R value of 0.031 based on 1279 observed reflections ([I>-3 σ(I)]). (II) belongs to the triclinic P-1 with a=6.838(3), b=6.879(3), c=10.130(3)Å, α=92.23(2), β=92.98(2), γ=107.65(3)°, and Dcalc=1.67 g cm-3 for Z=2. Refinement gave R=0.042 for 1543 observed reflections. (III) was found to be orthorhombic Pbca with a=7.259(3), b=13.449(3), c=18.090(5)Å, and Dcalc=1.64 g cmsu-3 for Z=8. Refinement produced R=0.026 for 767 observed reflections. In (I) the electron-withdrawing formyl group is found trans to the nitrosyl. The same holds for the cyano group in (II), but the amino function in (III) is not trans to any of the tripod ligands.
|Original language||English (US)|
|Number of pages||12|
|Journal||Journal of Crystallographic and Spectroscopic Research|
|State||Published - Dec 1 1988|