Ligand bending and tilted coordination in the coordinatively unsaturated NHC complex lateral-bis(N,N′-dineopentyl-benzimidazoline-2-ylidene)molybdenumtricarbonyl - Synthesis and structural investigations

Farman Ullah, Tibor Szilvási, Tamás Veszprémi, Peter G. Jones, Joachim Heinicke

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Reaction of free dineopentyl-benzimidazoline-2-ylidene 1 (ligand: np2bimy) with (η3-cycloheptatriene)Mo(CO)3, molar ratio 3:1, provides the coordinatively unsaturated lateral-(np2bimy)2Mo(CO)3 complex 2. Crystal structure analysis of 2 reveals an almost ideal cis-square pyramidal geometry with tilted coordination of the metal, interplanar angles of the np2bimy ligands to the C4Mo plane of about 70° and significant bending of the N-heterocyclic carbene rings towards each other. Quantum chemical calculations (B97-D/6-31G(d)[Mo:cc-pVTZ-PP] level of theory) reproduce this peculiar structure and show it to be more stable by 36 kJ/mol than the second energy-minimum structure with trigonal bipyramidal geometry and the carbene ligands in the axial positions. Calculations indicated no significant Mo-C(II) back-bonding or interactions of the empty d-orbital with adjacent p-orbitals of the ligands, implying that the ligand distortions, tilted coordination and the occurrence of a free coordination site are caused by the spatial demand of the N-substituents.

Original languageEnglish
Pages (from-to)22-27
Number of pages6
JournalJournal of Organometallic Chemistry
Volume783
DOIs
Publication statusPublished - May 1 2015

Keywords

  • Carbonyl complexes
  • Coordination modes
  • Ligand deformation
  • Molybdenum
  • N-heterocyclic carbenes
  • Steric hindrance

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Ligand bending and tilted coordination in the coordinatively unsaturated NHC complex lateral-bis(N,N′-dineopentyl-benzimidazoline-2-ylidene)molybdenumtricarbonyl - Synthesis and structural investigations'. Together they form a unique fingerprint.

  • Cite this