Imido complexes molecular structure

The bis-MeCsELi or bis-Cp framework is a useful template for organoimido and organophosphinidene complexes. Comproportionation of uranium(III) and ura-nium(V) metallocenes provides a route to dinuclear ura-nium(IV) imido complexes (equation 11). The molecular structure of [(MeC5H4)2U(NPh)]2 is depicted in (5). 

The chloro imido-amidinato titanium complex TiGl(NBut)[PhC(NSiMe3)2](py)2 reacts with LiCH2SiMe3 or with LiCH(SiMe3)2 in benzene to give rare examples of terminal imido monoalkyltitanium derivatives TiR(NBut)[PhG(NSiMe3)2](py) (Scheme 36). The molecular structure of the trimethylsilylmethyl derivative has been determined by X-ray diffraction.90... 

The binuclear tetramethyl complex [TiMe2(THF)(/x-NAr)]2 [Ar = w-C6H4-P(3,5-(CF3)2C6H3)2] can be prepared by methylation of the chloro parent compound with LiMe in Et20 at 0 °C (Scheme 77) and is stabilized by two imido bridges. The molecular structure of this complex has been determined by X-ray diffraction methods and shows that each Ti atom occupies the center of a trigonal bipyramid.152... 

The reaction of the zirconocene imido complex 800 with PdCl(Me)(COD) gives Zr/Pd heterobimetallic complexes 801 with bridging alkylideneamido ligands613 (Scheme 200). The molecular structures of the complexes 801 have puckered ZrN2Pd rings with Zr-Pd distances of 2.8135(5) A (Ar = Ph) and 2.8416(4) A (Ar =/>-tolyl), respectively. Upon treatment with HX (X = Cl, OPh), complexes 801 are converted to Cp2ZrX2 and //77/7i--PdCl(Me)(NH=GAr2)2. 

As noted above, the complexes of corroles with metals of the first transition series comprise the majority of reported metallocorroles. Many investigations have focused on the usual bioinorganic suspects, Cu and Fe. A number of computationally heavy reports on the electronic and molecular structures and spectroscopic properties of Cu corroles have been produced over the last few years, while the field has seen numerous attempts to formalize consensus electronic structural descriptions of Co and Fe corroles. There is also a rich literature describing the catalytic utility of high-valent Cr and Mn complexes with oxo, imido, or nitrido ligands, and a small amount of work has been performed on Ti and V corroles. Ni corroles have been reported in the literature as well, but investigations of their properties have often been folded into larger studies. 

Figure 3 Half-sandwich imido complexes of the heavier Group 5 metals, and the molecular structure of Nb NMe)Cl2Cp ...

At 220 °C and 50 atm CO, Ru3(CO)i2 is a catalyst in CH3CN for the conversion of 1 into 2 and 3 [9]. The selectivity in the synthesis of 2 was similar to the one observed with Fe(CO)s. As it is known that aromatic nitro compounds, and more easily nitroso compounds, react with Ru3(CO)i2 to give imido complexes in which the nitrogen atom is coordinated to all of the three ruthenium atoms of the cluster skeleton [10-12], the nitrene complex 4, possible intermediate in the reaction, has been synthesised (eq. 2) and its crystal and molecular structure determined [9] ... 

An EXAFS study of surface species [(=SiO)2Ta(=NH)(NH2)] yielded spectra that can be satisfactorily fitted by a model based principally on a Ta bissiloxy amido imido structure that yielded the bond distances of 1.787(19) A for Ta=N, 1.892(9) A for Ta-O and 1.97(3) A for Ta-N. These distances are in good agreement with values obtained from crystallographic data for molecular imido amido Ta(=N-) (-0-) (-N<)j, type complexes and fall within ranges usually observed for these distances. 

The reactions of rhenium(V) oxo-alkyl-phosphine complexes with various alkynes were studied and the X-ray crystal structure of [Re(=0)Mc3(PhC>CPh)] was reported OO. The synthesis of a number of ibenium(I) tris-alkyne complexes was reported and [Re(OSiMe3)(MeCjCMe)3] characterised by X-ray diffraction Oi. The synthesis of a series of bis-imido alkyne and imido bis-alkyne rhenium complexes of the type [Re(NAr)2Cl(RCSCR)] and [ReCl(NAr)(NpGCNp)2] has been reported302 and the electrtxiic structures of the compounds investigated by Extended Huckel molecular mbital calculations. 

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