Structure of ([eta superscript 5]-cyclopentadienyl)([eta superscript 6]-p-isopropylnitrobenzene)iron(II) trifluoroacetate at 198 K

Abstract

[Fe(C[subscript 5]H[subscript 5])(C[subscript 9]H[subscript ll]NO[subscript 2])].C[subscript 2]F[subscript 3]O[subscript 2], (I), M[subscript r] = 399[middle dot]1, monoclinic, P2[subscript 1]/c, a = 8[middle dot]995 (2), b = 10[middle dot]641 (2), c=17[middle dot]538 (5) [Angstrom], [beta]=95[middle dot]22 (2) °, V = 1671[middle dot]7 (8)[Angstrom][superscript 3], Z = 4, D[subscript x] = 1[middle dot]586 g cm [superscript -3], [lambda](Mo [kappa][alpha]) =0[middle dot]71069 [Angstrom], [mu] = 9[middle dot]50 cm[superscript -1], F(000) = 816, T= 163 K, R = 0[middle dot]0648 and wR = 0[middle dot]0713 for 2502 reflections [I[greater than or equal to] 3[sigma](I)]. The phenyl ring exhibits a significant asymmetry in the C--C and Fe--C bond lengths. C(3)--C(4) and C(4)--C(5) [1[middle dot]427 (6) and 1[middle dot]424 (6)[Angstrom]] are longer than the rest of the phenyl bonds; the longest bond with the Fe atom is that of C(4) [2[middle dot]131 (4) [Angstrom]. The lengthening of these bonds may be attributed to the bulky isopropyl group and the presence of H(7) on the same side of the phenyl ring as the FeCp moiety. The phenyl ring and the cyclopentadienyl (Cp) are nearly parallel to each other [dihedral angle 1[middle dot]3 (2)°], and the plane of the nitro group is twisted by an angle of 5[middle dot]7 (2) ° with respect to the phenyl ring. The Fe atom is closer to the phenyl ring [1[middle dot]5451 (8) [Angstrom]] than the Cp ring [1[middle dot]6711 (9)[Angstrom]]; this phenomenon was also seen in all similar compounds studied in this laboratory. Each acetyl O atom is involved in a close contact with an aromatic H atom. For C(3)--H(3)[middle dot][middle dot][middle dot]O(3) (1-x, - 0[middle dot]5 + y, 0.5 - z): C--H = 0[middle dot]86 (5), H[middle dot][middle dot][middle dot]O = 2[middle dot]59 (6), C[middle dot][middle dot][middle dot]O = 3[middle dot]207 (6) Angstrom], C--H[middle dot][middle dot][middle dot]O = 130 (3) °. For C(5)---H(5)[middle dot][middle dot][middle dot]O(4) (1 - x, 0[middle dot]5 + y, 0[middle dot]5 - z): C--H = 0[middle dot]80 (5), H[middle dot][middle dot][middle dot]O = 2[middle dot]46 (6), C[middle dot][middle dot][middle dot]O = 3[middle dot]063 (6) [Angstrom], C--H[middle dot][middle dot][middle dot]O = 132 (3) °.