330433-98-2Relevant academic research and scientific papers
Regiospecific influences of phenyl ring substituents in monoimido complexes of tantalum and tungsten and bis imido complexes of molybdenum
Nielson, Alastair J.,Glenny, Mark W.,Rickard, Clifton E. F.,Waters, Joyce M.
, p. 4569 - 4578 (2007/10/03)
Imido exchange of [TaCl3(NCMe3)(py)2] with 2-/erf-butylaniline in refluxing benzene and crystallisation of the product from CH2C12 gave the anionic complex [Hpy][TaO4(C6H4CMe3-2)(py)] 1. X-Ray structural analysis shows that with the Ta-N-C bond angle at 165.1(5)° two of the tcrt-buly substituent methyl groups sit above two meridional chloro ligands but NMR spectroscopy indicates that the fe/7-butyl group can still rotate in solution. Reaction of isocyanates ArNCO [Ar = C10H7 (naphthyl), C6H4CMer2 or C6H4Ph-2] with VOC14 in refluxing benzene gave [{WC14(NC10H7)} J 2, [{WCl4(NC6H4CMe3-2)}J 3, and [{WCl4(NC6H4Ph-2)} J 4 which NMR spectra show convert from two species into one in CDC13. In refluxing toluene, 2-/e/7-butylphenyl isocyanate also forms the metallacyclic amido complex [WCl4{NHC6H4(CMe2CH2)-2(C,AO}] 5. The d1 complexes [WCl3(NC10H7)(PMe3)2] 6, [VCl3(NC6H4CMe3-2)(PMe3)2] 7, [VCl3(NC6H4Ph-2)(PMe3)2] 8, [WCl3(NC10H7)(PMe2Ph)2] 9 and [WC13(NC10H7)(PMePh2)2] 10 were prepared, and show hindered imido ligand aryl C-N bond rotation. A crystal structure determination of 6 shows the naphthyl ring C-8 proton positioned between a chloro and phosphine ligand. Also prepared to demonstrate hindered aryl C-N bond rotation were the d2 complexes [WCl2(NC10H7)(PMe3)3] 11, [WCl2(NC6H4CMe3-2)(PMe3)3] 12, [WCl2(NC6H4Ph-2)(PMe3)3] 13 and [VCl2(NC10H7)(PMe2Ph)3] 14. Crystal stucture determinations show the /erf-butyl group in 12 located above a chloro ligand and the phenyl group in 13 located between a chloro and phosphine ligand. They also show the methyl and isopropyl substituents in [MoClj(NC6H3Me-2-Pr'-6)2(dme)] 15 form an anti configuration and in [MoCl2(NC6H4CMe3-2)2(dme)] 16 a syn configuration is identified where the Mo-N-C bond angles are determined by steric effects and crystal packing forces. The Royal Society of Chemistry 2000.
