Terminally Coordinated AsS and PS Ligands

Abstract

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)W[triple chemical bond]As] and [(N(3)N)W[triple chemical bond]P], respectively, with cyclohexene sulfide. Both complexes present very short W--E and E--S 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 sigma (1 sigma and 2 sigma) and two degenerate pi molecular orbitals (MOs) (1 pi and 2 pi). The 1 sigma MO is a bonding MO extended over the N(ax)-W-E-S core, whereas the 2 sigma MO is localised mainly on the E-S fragment. The 1 pi set is a E-S localised bonding molecular orbital, whereas the 2 pi 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 E--S and the W--E 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 pi system in complexes 3-5 is best described by two three-centre four-electron bonds.

Hydrolysis of Dinuclear Ruthenium Complexes [{CpRu(PPh3)2}2(μ,η1:1‐L)][CF3SO3]2 (L=P4, P4S3): Simple Access to Metal Complexes of P2H4 and PH2SH

“…In [{Cr(CO) 5 } 2 P(Me) 2 SH] a P À S distance of 2.019 and a Cr-P-S angle of 113.86 are found. [35] The formally double bonded P À S distance of 1.941(2) found for a tungsten PS derivative [36] is definitely shorter than the present one. HA C H T U N G T R E N N U N G { 31 P} spectra in the PH 2 region are consistent with an AA'MXX' spin system (in which A, A' and M are the phosphorus atoms of the triphenylphosphane and PH 2 SH ligands, respectively, and X, X' are the hydrogen atoms of the PH 2 group), the pattern of which can be successfully simulated (Figure 7) only on the basis of an exchange process between P A and P A' (k exch = 45.6 s À1 ).…”

Electronic Structure of Linearly Coordinated EQ Complexes of the Type [(N3N)W(EQ)] [N3N = N(CH2CH2NSiMe3)3; E = P, As, Sb, Bi; Q = O, S, Se, Te]: A DFT Study

“…Recently, we reported the results of calculations on [(N 3 N)W(ES)] [N 3 N=N(CH 2 CH 2 NSiMe 3 ) 3 ; E = P, As and Sb] 16. Inclusion of the Me 3 Si substituents on the imido nitrogen atoms was important for achieving good agreement of our calculated geometries with structural parameters obtained from X‐ray crystallographic analyses of these complexes.…”

“…We assume this is due to the strong electron‐donating properties of these substituents. Most significantly, our study demonstrated that π bonding in the W–E–Q unit can best be described as two three‐centre four‐electron bonds (3c‐4e) 16. To further our understanding of the structural and electronic properties of η 1 ‐coordinated EQ complexes, we have extended our analysis to the complete series of [(N 3 N)W(EQ)] complexes (E = P, As, Sb, Bi; Q = O, S, Se and Te).…”

“…Selected bond lengths and angles for the calculated structures are provided in Table 1. Our benchmarks for the optimised structures are the complexes 1b and 2b , whose crystal structures were reported recently 16. The calculated geometrical parameters for 1b (P–S 1.94 Å; W–P 2.15 Å) and 2b (As–S 2.05 Å; W–As 2.25 Å) compare excellently with the reported experimental values [E–S 1.9410(16) Å and 2.048(2) Å; W–E 2.1579(10) Å and 2.2557(8) Å for 1b and 2b , respectively] 16.…”

“…Indeed, Cummins et al reported the isolation and characterisation of the PO [(ArRN) 3 Mo(PO)]14 and PS [(ArRN) 3 Mo(PS)]9,15 complexes, which were prepared by oxidation of the corresponding phosphido complex [(ArRN) 3 Mo≡P] with dimethyldioxirane and sulfur, respectively. More recently, Scheer et al reported preparation of the η 1 ‐coordinated PS and AsS complexes [(N 3 N)W(ES)] (E = P and As)16 by oxidation of the terminalphosphido and arsenido complexes [(N 3 N)W≡E] (E = P and As) with cyclohexene sulfide.…”