Amidine and guanidine complexes of manganese and molybdenum. Crystal structures of (η-cyclopentadienyl)(N,N′-diphenylguanidino)- and (η-cyclopentadienyl)(N,N′,N ″-triphenylguanidino)-dicarbonylmolybdenum(II)

Authors:
  • JMJosé R. da S. Maia
    José R. da S. Maia
  • PGPauline A. Gazard
    Pauline A. Gazard
  • MKMelvyn Kilner
    Melvyn Kilner
  • ABAndrei S. Batsanov
    Andrei S. Batsanov
  • JHJudith A. K. Howard
    Judith A. K. Howard
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Abstract
Reactions of N,N′-diphenyl- and N,N′,N″-triphenylguanidine with [MnBr(CO)5] gave cis-[MnBr{PhNC(NHR)NHPh}(CO)4], fac-[MnBr{PhNC(NHR)NHPh}2(CO)3] and [Mn{PhNC(NHR)NPh}(CO)4] (R = H or Ph), the last complex being formed at higher temperatures with an excess of ligand. In reactions of these guanidines with [MoCl(η-C5H5)(CO)3], HCl was eliminated and [Mo(η-C5H5){PhNC(NHR)NPh}(CO)2] complexes (R = H or Ph) formed. Crystal structures of these molybdenum complexes have been determined, revealing symmetrically chelating co-ordination of the guanidino ligands (in close semblance of corresponding amidino-complexes) with the four-membered metallacycle planar for R = Ph but unusually (by 21°) folded for R = H due to hydrogen bonding of an uncommon type. Reaction of lithio-N,N′-di-p-tolylbenzamidine with [Mo(η-C7H7)(CO)3]BF4 yielded [Mo{η-C7H7N(p-MeC6H4)C(Ph)NC6H4Me-p}(CO)3], consistent with nucleophilic attack at the ring, followed by nitrogen co-ordination at the metal by a pendant amidine group.