Electronic structure factors of Si-H bond activation by transition metals. Valence photoelectron spectra of (. eta. sup 5 -C sub 5 H sub 4 CH sub 3 )Mn(CO)(PMe sub 3 )HSiCl sub 3 and (. eta. sup 5 -C sub 5 H sub 4 CH sub 3 )Mn(CO)(PMe sub 3 )HSiHPh sub 2 (Me = CH sub 3 , Ph = C sub 6 H sub 5 )

Journal Article · Tue Mar 06 23:00:00 EST 1990 · Inorganic Chemistry; (USA)

DOI:https://doi.org/10.1021/ic00330a015· OSTI ID:6835583

Lichtenberger, D L; Rai-Chaudhuri, A ^[1]

---

1. Univ. of Arizona, Tucson (USA)

The valence photoelectron spectra of ({eta}{sup 5}-C{sub 5}H{sub 4}CH{sub 3})Mn(CO)(L)HSiCl{sub 3} and ({eta}{sup 5}-C{sub 5}H{sub 4}CH{sub 3})Mn(CO)(L)HSiHPh{sub 2}, where L is CO or P(CH{sub 3}){sub 3}, are compared to determine the effect of ligand substitution at the metal center on Si-H bond activation. Metal centers that are more electron rich may promote more complete oxidative addition of the Si-H bond to the metal. The shifts in the metal and ligand ionization energies and the relative intensities of ionizations in the He I and He II photoelectron experiments show that the metal in ({eta}{sup 5}-C{sub 5}H{sub 4}CH{sub 3})Mn(CO)(PMe{sub 3})HSiCl{sub 3} is best represented by a formal oxidation state of III (d{sub 4} electron count). This indicates nearly complete oxidative addition of the Si-H bond to the metal center and results in independent Mn-H and Mn-Si bonds. In contrast, the splitting and intensity pattern of the metal-based ionizations of ({eta}{sup 5}-C{sub 5}H{sub 4}CH{sub 3})Mn(CO)(PMe{sub 3})HSiHPh{sub 2} reflect the formal d{sup 6} electron count of a metal corresponding to oxidation state I. The extent of electron charge density shift from the metal to the ligand is also small, as evidenced by the negligible shifts of these ionizations from those of the related ({eta}{sup 5}-C{sub 5}H{sub 4}CH{sub 3})Mn(CO){sub 2}(PMe{sub 3}) complex. These observations indicate that the electronic structure of the Si-H interaction with the metal in this complex is in the initial stages of Si-H bond addition to the metal, before oxidative addition has become prevalent. 25 refs., 6 figs., 1 tab.

• DOE Contract Number: AC02-80ER10746
• OSTI ID: 6835583
• Journal Information: Inorganic Chemistry; (USA), Journal Name: Inorganic Chemistry; (USA) Vol. 29:5; ISSN 0020-1669; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
AROMATICS
CARBONYLS
CHEMICAL BONDS
CHLORINE COMPOUNDS
COMPLEXES
DATA
ELECTRONIC STRUCTURE
EXPERIMENTAL DATA
HALOGEN COMPOUNDS
HYDROCARBONS
INFORMATION
MANGANESE COMPLEXES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOMETALLIC COMPOUNDS
SILICON COMPLEXES
TRANSITION ELEMENT COMPLEXES