Cooperative effects in π-ligand bridged dinuclear complexes XXII. New dinuclear bis(cyclopentadienediyl)ketone complexes containing molybdenum, tungsten, cobalt and iron

Cyclopentadienyl chromium and tungsten complexes with halide, methyl and σ-phenylethynyl ligands: Structures of (η5-C5H5)Cr(NO)2(–CC–C6H5), (η5-C5H5)Cr(NO)2I and [(η5-C5H4)-COOCH3]W(CO)3Cl

“…The shorter bond lengths in Å of Cr-C(11) (2.193 (2)) and Cr-(C11A) (2.193 (2)), and the longer bond length of Cr-C(9) (2.224(3)) were observed. As well, C(1) along The bond length of Cr-ethynyl carbon(C(1)) (2.013(3) Å) is short, compared to 2.241(7) Å in complex Cr 3 (dpa) 4 (C"C-Ph) 2 (dpa = 2,2-dipyridylamide) [17]. Simple Cr 0 -C(sp 3 ) single-bond distances are expected to fall in the range of 2.20-2.24 Å [18].…”

“…Earlier [6], we reported the unequivocal assignments of C(2,5) and C (3,4) on the Cp ring of the (cyclopentadienyl)dicarbonylnitrosylchromium (hereafter called cynichrodene) derivatives bearing electron-withdrawing substituents in 13 C NMR spectra. The opposite correlation on the assignments between ferrocene and cynichrodene was a surprising finding.…”

“…It is interesting to note the slopes of 2D spectra of compounds 10 and 13 are opposite, one is positive and the other one is negative. Accordingly, the unambiguous assignments were made: C(2,5) and C (3,4) of Cp(Cr) resonates at d 102.37 and 100.01 for compound 10, respectively; C(2,5) and C (3,4) of Cp(W) resonates at d 91.91 and 95.47 for compound 13, respectively. The assignment is a kind of surprise.…”

“…The unequivocal assignments of 13 C chemical shifts for 6 and 12 were correlated well with the ab initio calculations from the X-ray data of 6 and 12. The average charges of C(2,5) and C (3,4) are À0.1593 and À0.2186 for compound 6, and À0.2057 and À0.1711 for compound 12 (Table 4a).…”

“…In the case of CpCr(NO) 2 Cl (1), only three complexes, (C 5 H 4 COOCH 3 )Cr(NO) 2 Cl (6) [1], (Fc-C(O)-C 5 H 4 )Cr(NO) 2 Cl [2], and Cp 2 Ti(CH 3 2 Cl} [3] are reported in the literature. For the analogue of CpCr(NO) 2 CH 3 (4) there is only one, (C 5 H 4 COOCH 3 )Cr(NO) 2 CH 3 [1], and for complex CpW(CO) 3 CH 3 there are 18 [4]. For Cp derivatives of compound CpCr(NO) 2 -(C"C-C 6 H 5 ) (5) and CpW(CO) 3 (C"C-C 6 H 5 ) [5], there are none.…”