Photoelectron spectroscopic study of bonding in inorganic and organometallic compounds. [Boron trihalides; silyl amines; thiazyl fluorides; borane adducts; transition metal complexes with isocyanides and olefins]

Technical Report · Wed May 01 04:00:00 EDT 1985

OSTI ID:5786880

Beach, D B

The gas-phase x-ray photoelectron spectra of boron trihalides, silyl amines, and thiazyl fluorides were obtained. It was found that the order of pi stabilization in the boron trihalides is BF/sub 3/ > BCl/sub 3/ greater than or equal to BBr/sub 3/ > BI/sub 3/. The nitrogen lone-pair orbitals of trisilylamine and tris(trimethyl)silylamine were about 1 eV more stable than a hypothetical nonbonded nitrogen lone pair, indicating N p pi ..-->.. Si d pi bonding. Sulfur d orbital participation is needed to rationalize the corrected ionization potentials of NSF and NSF/sub 3/. The charge distributions and atomic orbital character of NSF and NSF/sub 3/ were obtained. The same technique was used to study sigma and pi interactions in borane adducts of CO and CNCH/sub 3/, iron tetracarbonyl olefin complexes, and transition metal complexes of isocyanides. Borane to carbon monoxide pi bonding is important in BH/sub 3/CO, and the increase in C--O and C--N bond strength observed when BH/sub 3/CO and BH/sub 3/CNCH/sub 3/ form borane adducts is due to rehybridization of the sigma orbitals on carbon. The equatorially coordinated ethylene ligand of Fe(CO)/sub 4/C/sub 2/H/sub 4/ is a better pi acceptor of electron density from the equatorial metal orbitals than the CO ligand it replaced, but a poorer pi acceptor to the Fe d/sub xz/, d/sub yz/ orbitals. By comparing the bonding of CNCH/sub 3/ to CO in Fe(CO)/sub 4/CNCH/sub 3/, it was shown that CNCH/sub 3/ is a weaker sigma donor and pi acceptor than CO in this complex, and that filled pi orbital interactions are relatively more important for CNCH/sub 3/ than for CO.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5786880
• Report Number(s): LBL-19459; ON: DE85011975
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ADDUCTS
ALKENES
AMINES
BORANES
BORON COMPOUNDS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CHALCOGENIDES
CHEMICAL BONDS
COMPLEXES
ELECTRON SPECTROSCOPY
ETHYLENE
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
IRON COMPLEXES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SILICON COMPOUNDS
SPECTROSCOPY
TRANSITION ELEMENT COMPLEXES