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  • Author: Max Herberhold x
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Arylazo complexes of the type CpCr(CO)2-(N = N-C6H4-X(p)) (X = H, OCH3, CH3, F, NO2) have been obtained by the reaction of CpCr(CO)3Na with p-substituted aryldiazonium tetrafluoroborates in glacial acetic acid.

Irradiation of cis-M. (CO) 4L′2 (M = Cr, Mo, W; L′ = 1,3-dimethyl-4-imidazoline-2-ylidene) in solution leads to photoisomerisation to the corresponding trans-M (CO)4L′2 complexes which are reconverted thermally to the thermodynamically more stable cis-isomers. In the presence of pyridine, the photoreaction of cis-Mo (CO) 4L′2 results in the formation of both fac-Mo (CO)3 (py) L′2 and trans-Mo (CO)4L′2.

Displacement of the CO ligand in CpV(NO)2CO (Cp = η5-cyclopentadienyl) by various Lewis bases (L) in solution leads to a series of (28) complexes CpV(NO)2L which were characterised by the 51V NMR chemical shift, the 13C and 1H NMR chemical shifts of the cyclopentadienyl ring, and by the NO stretching frequencies of the two nitrosyl ligands. The chemical shift δ(51V) varies over the range of ca. -1300 and -500 ppm depending on the nature of L, whereas δ(13C) of the cyclopentadienyl ring varies only between 98 and 102 ppm. The shielding of the 51V and 13C nuclei decreases as the electronegativity of the ligand atom bound to the metal increases in the order P <S <N <O

The tetramethoxyethylene (TME) complexes, Fe (CO)4 (TME) and C5H5Mn (CO)2 (TME), have been prepared in which the olefin is symmetrically coordinated. The IR spectra indicate that TME possesses considerable acceptor properties.

The new dinuclear [1.1]metallocenophanes, bis(dimethylsila)-[1.1]ferrocenophane (2a) and bis(dimethylsila)-[1.1]ruthenocenophane (2b), were synthesized by the reaction of dilithium di(cyclopentadienyl)dimethylsilane with FeCL·2 thf and RuCl2·4 dmso in tetrahydrofuran solution, and compared with the known bis(methylene)-bridged analogues [1.1]ferrocenophane (8a) and [1.1]ruthenocenophane (8b), respectively. A series of mononuclear [n]ruthenocenophanes including 1,1,2,2 -tetramethyl-[2]ruthenocenophane (10b), 1,2 - bis(dimethylsila)-[2]ruthenocenophane (3b), 1,3-bis(dimethylsila)-2-oxa-[3]ruthenocenophane (4b) and 1,4-bis(dimethylsila)-[4]ruthenocenophane (5b) was also prepared and studied together with the corresponding [n]ferrocenophanes, 10a and 3a-5a. 1,1′-Dilithioruthenocene was found to be a versatile starting material for the synthesis of silicon-substituted ruthenocene derivates such as Ru(C5H4-R)2 (R = SiMe3 (6b), Si2Me5 (7b)) and [n]ruthenocenophanes (3b- 5b). A complete set of 1H, 13C and 29Si NMR data is presented, and the available structural data are discussed with respect to the tilt angle a of the cyclopentadienyl ring ligands which is larger in the more strained [2]ruthenocenophanes than in the corresponding [2]ferrocenophanes.


A nitromethane solution of NS+PF6 -, obtained in situ from N3S3Cl3 and AgPF6 (1:3), reacts with benzene tricarbonyl chromium in acetonitrile solution to give the thionitrosyl-containing salt [Cr(NS)(NC-Me)5](PF6)2 (1)-In the presence of Zerf-butyl isocyanide and Zn powder, 1 is reduced to [Cr(NS)(CN-CMe3)5F6 (3), while subsequent oxidation of 3 with either NOPF6 or AgPF6 leads to [Cr(NS)(CN-CMe3)5](PF6)2 (5). The thionitrosyl-containing salts 1, 3 and 5 are compared with the corresponding nitrosyl complexes.

In contrast to tetranuclear bis(pentane-2,4-dionato)-cobalt(II), Co4(acac)8, which is cleaved by nitric oxide to give the adduct Co(acac)2(NO), the mononuclear tris(pentane-2,4-dionato)cobalt(III), Co(acac)3, is attacked by NO at the chelate ligands. The photonitrosylation of Co(acac)8 in benzene or toluene solution leads to the oximato complex tris(3-hydroxyimino-pentane-2,4-dionato)cobalt.

The first seleninylamine, tBuNSeO, was prepared from tert-butylamine, tBuNH2, and SeOCl2 (3:1). The selenium diimide Se(NBut)2 was isolated from the corresponding reaction of tBuNH2 and SeCl4 (6:1); it decomposes at ambient temperature to give cyclic Se3(NBut)2. The new compounds were characterized on the basis of their IR , 1H and 13C NMR and mass spectra.


Trimetallic complexes Fe(C5H4-SMLn)2 (MLn = M(NO)2Cp (M = Cr. Mo, W) and M(CO)3 Cp (M = Mo, W)) containing a ferrocene-1.1'-dithiolato bridge between two group VI metals were prepared and spectroscopically characterized. The mixed species Fe(C5H4-SCr(NO)2Cp)(C5H4-SW(CO)3Cp) and the bimetallic precursors Fe(C5H4-SMLn)(C5H4-SH), (MLn=M(NO)2Cp(M=Cr,Mo), M(CO),Cp(M=Mo,W)). were also obtained. The ferrocene-thiolato ligands are stronger electron-donors than phenyl-and methyl-thiolato ligands.


The reactions of the bifunctional bis(chloroarsino) compounds MeCH[As(But )Cl]2 and RCH[AsCl2]2 (R = H, Me) with the salt K2SN2 lead to rings and cages containing arsino-substituted sulfur diimide units.