Reaction Products of Group Vib Metal Carbonyl Compounds With Organic Compounds of Trivalent Group Va Elements

a b s t r a c tA radical species characterized by a large g-anisotropy and a clearly resolved hyperfine structure with 95/97 Mo and 31 P nuclei is formed, at 77 K, by radiolysis of a single crystal of Mo(CO) 5 PPh 3 . The corresponding EPR signals disappear irreversibly with increasing temperature and the angular dependence of the various coupling constants imply a spin delocalization of $60% and $4% on the molybdenum and the phosphorus atoms, respectively and are, a priori, consistent with the trapping of a one-electron deficient centre. The ability of DFT to predict the EPR tensors for a 17-electron Mo (I) species is verified by calculating the g-tensor and the various 14 N and 13 C coupling tensors previously reported by Hayes for [Mo(CN) 5 NO] 3À . Calculations at the B3LYP/ZORA/SOMF level of theory show that, in contrast to Mo(CO) 5 PH 3 , one-electron oxidation of Mo(CO) 5 PPh 3 causes an appreciable change in the geometry of the complex. The g-tensor and the 95/97 Mo and 31 P isotropic and anisotropic coupling constants calculated for [Mo(CO) 5 PPh 3 ] + Á confirm the trapping of this species in the irradiated crystal of Mo(CO) 5 PPh 3 ; they also show that the conformational modifications induced by the electron release are probably hindered by the nearby complexes.

show abstract

“…Mo(CO) 5 PPh 3 was synthesized following an already published procedure [15]. The crystal structure (triclinic) has been reported.…”

Section: Methodsmentioning

confidence: 99%

Single-crystal EPR study and DFT structure of the [Mo(CO)5PPh3]+· radical cation

Sidorenkova

Berclaz

Ndiaye

et al. 2009

Journal of Physics and Chemistry of Solids

View full text Add to dashboard Cite

show abstract

“…Syntheses of Cr(CO) 5 P(C 6 H 5 ) 3 , Mo(CO) 5 P-(C 6 H 5 ) 3 , and Mo(CO) 5 P(C 6 H 5 ) 3 have been published. 14 The syntheses of Cr(CO) 5 P(H)(C 6 H 5 ) 2 and W(CO) 5 P(H)(C 6 H 5 ) 2 have been carried out by adapting the method reported by Mathey et al for W(CO) 5 P(C 6 H 5 )H 2 . 15 Crystal Structure.…”

Section: Methodsmentioning

confidence: 99%

EPR and DFT Studies of the Structure of Phosphinyl Radicals Complexed by a Pentacarbonyl Transition Metal

et al. 2006

View full text Add to dashboard Cite

Paramagnetic complexes M(CO) 5 P(C 6 H 5 ) 2 , with M ) Cr, Mo, W, have been trapped in irradiated crystals of M(CO) 5 P(C 6 H 5 ) 3 (M ) Cr, Mo, W) and M(CO) 5 PH(C 6 H 5 ) 2 (M ) Cr, W) and studied by EPR. The radiolytic scission of a P-C or a P-H bond, responsible for the formation of M(CO) 5 P(C 6 H 5 ) 2 , is consistent with both the number of EPR sites and the crystal structures. The g and 31 P hyperfine tensors measured for M(CO) 5 P-(C 6 H 5 ) 2 present some of the characteristics expected for the diphenylphosphinyl radical. However, compared to Ph 2 P • , the 31 P isotropic coupling is larger, the dipolar coupling is smaller, and for Mo and W compounds, the g-anisotropy is more pronounced. These properties are well predicted by DFT calculations. In the optimized structures of M(CO) 5 P(C 6 H 5 ) 2 (M ) Cr, Mo, W), the unpaired electron is mainly confined in a phosphorus p-orbital, which conjugates with the metal d xz orbital. The trapped species can be described as a transition metal-coordinated phosphinyl radical.

show abstract

“…This route can theoretically generate both cis-and trans-substituted tetracarbonyl complexes as the substitution products [5,6], while the cis-isomer is typically obtained in higher yield [37]. Alternatively, a carbonyl ligand of a homoleptic metal carbonyl complex can be replaced by a pnictogen ligand [38,39], and the resulting substituted metal pentacarbonyl complex can then be subjected to carbene synthesis (Figure 2(b)) [4]. This method generates solely the cis-substituted tetracarbonyl complex [4], as the pnictogen ligand reduces the electrophilicity of the carbonyl ligand trans to itself.…”

Section: Synthesismentioning

confidence: 99%

“…and trans-isomers can be achieved by means of column chromatography [6] or crystallization, [40] however, interconversion of the two stereoisomers is possible [13,41]. Carbonyl substitution requires metal-carbonyl bond cleavage, which can be facilitated thermally [38] or photochemically [39]. Thermal methods are preferred over ultraviolet irradiation, as this method generates fewer side-products during carbonyl substitution of a Fischer carbene complex [42].…”

Section: Synthesismentioning

confidence: 99%

Molybdenum(0) Fischer ethoxycarbene complexes: Synthesis, X-ray crystal structures and DFT study

et al. 2017

View full text Add to dashboard Cite

The synthesis and structural investigations are presented of molybdenum(0) Fischer carbene complexes with general formula [L(CO) 4 MoC(OEt)(Ar)] with L = CO, PPh 3 , AsPh 3 and Ar = 2-thienyl, 2-furyl, 2-(N-methyl)pyrrolyl, 2,2'-bithienyl. The X-ray crystal structures, along with NMR and IR spectroscopy, revealed a cis-orientation of the carbene and pnictogen ligands (PPh 3 or AsPh 3) for all the substituted complexes. A density functional theory study of all possible conformers indicated, in agreement with experimental results, that the cisisomers (PPh 3 or AsPh 3 cis relative to the carbene ligand) are more stable than the corresponding trans-isomers, and that most stable conformers have the aryl group syn to the ethoxy group for Ar = 2-thienyl, 2-(N-methyl)pyrrolyl, 2,2'-bithienyl and anti to the ethoxygroup for Ar = 2-furyl.

show abstract

Reaction Products of Group Vib Metal Carbonyl Compounds With Organic Compounds of Trivalent Group Va Elements

Cited by 34 publications

References 0 publications

Single-crystal EPR study and DFT structure of the [Mo(CO)5PPh3]+· radical cation

Single-crystal EPR study and DFT structure of the [Mo(CO)5PPh3]+· radical cation

EPR and DFT Studies of the Structure of Phosphinyl Radicals Complexed by a Pentacarbonyl Transition Metal

Molybdenum(0) Fischer ethoxycarbene complexes: Synthesis, X-ray crystal structures and DFT study

Contact Info

Product

Resources

About