Breaking an electronically preferred symmetry by steric effects in a series of [Ir(biph)X(QR<inf>3</inf>)<inf>2</inf>] compounds (X = Cl or I, Q = P or As)

Gregori Ujaque, Feliu Maseras, Odile Eisenstein, Louise Liable-Sands, Arnold L. Rheingold, Wenbin Yao, Robert H. Crabtree

Research output: Contribution to journalArticleResearchpeer-review

25 Citations (Scopus)

Abstract

A hybrid quantum mechanical/molecular mechanics IMOMM (B3LYP : MM3) method has been applied to a series of five-coordinate 16-electron d6ML5IrIIIcompounds having a relatively flat potential for a distortion from Y to T geometry and for which crystal structures have been obtained. In this series of type [Ir(biph)X(QPh3)2] (biph = biphenyl-2.2′-diyl; Q = P, X = Cl, 2a; Q = As, X = Cl, 2b; Q = P, X = I, 2c), the halide is found to lie in the (biph)Ir plane but off the C2axis of the {Ir(biph)Q2} fragment by a variable angular distortion φ. While φ = 0 is preferred electronically for [Ir(C4H4)Cl(PH3)2], the steric bulk of the real systems 2a-2c leads to φ taking experimental values of 8.2-17.2°. The observed deviation of the halide from the C2axis is shown by IMOMM to be the result of a direct interaction of the phenyl substituents of the axial ligands with the equatorial ligands and not to an electronic effect. The crystal structures for 2b and 2c have been determined.
Original languageEnglish
Pages (from-to)1493-1498
JournalNew Journal of Chemistry
Volume22
Issue number12
DOIs
Publication statusPublished - 1 Jan 1998

Fingerprint Dive into the research topics of 'Breaking an electronically preferred symmetry by steric effects in a series of [Ir(biph)X(QR<inf>3</inf>)<inf>2</inf>] compounds (X = Cl or I, Q = P or As)'. Together they form a unique fingerprint.

Cite this