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Terminally Coordinated AsS and PS Ligands
Author(s) -
Balázs Gábor,
Green Jennifer C.,
Scheer Manfred
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200600975
Subject(s) - natural bond orbital , chemistry , crystallography , molecular orbital , molecule , single bond , sulfide , density functional theory , stereochemistry , computational chemistry , group (periodic table) , organic chemistry
The terminal AsS and PS complexes [(N 3 N)W(ES)] (N 3 N=N(CH 2 CH 2 NSiMe 3 ) 3 ; E=P ( 3 ), As ( 4 )) were synthesised by reaction of [(N 3 N)WAs] and [(N 3 N)WP], respectively, with cyclohexene sulfide. Both complexes present very short WE and ES bond lengths. The bonding was investigated by density functional theory (DFT) calculations using the fragment calculation method and natural bond orbital (NBO) analysis. According to the fragment analysis, in which the complexes were separated in an ES and a (N 3 N)W fragment, the bonding in complexes 3 , 4 and [(N 3 N)W(SbS)] ( 5 ) is realised over a set of two σ (1σ and 2σ) and two degenerate π molecular orbitals (MOs) (1π and 2π). The 1σ MO is a bonding MO extended over the N ax ‐W‐E‐S core, whereas the 2σ MO is localised mainly on the E–S fragment. The 1π set is a E–S localised bonding molecular orbital, whereas the 2π set is in phase with respect to W–E but in antiphase with respect to E–S. Both methods indicate bond orders around two for both the ES and the WE bonds. The polarity of the complexes was examined by Hirshfeld charge analysis. This shows that complexes 3 and 4 are only slightly polarised, whereas 5 is moderately polarised toward the sulphur. As suggested by the computational results, the π system in complexes 3 – 5 is best described by two three‐centre four‐electron bonds.