Distibines complexes

In order to describe the different conformations in distibines or in distibine complexes, the torsion angles Ep-Sb-Sb-Ep (cp) for the free ligand... 

The bis-adducts are stable in the solid state at low temperatures. They dissociate in solution at ambient temperature. In the case of Me2Sb-SbMe2 a stable complex was formed only with the sterically hindered and less electrophilic t-Bu3Al. X-ray crystal structure analyses for [( -Bu)3M(R2Sb-SbR2)M( -Bu)3] (R = Me, Et M = Al, Ga) revealed that the distibine ligands adopt the anti conformation (Structural parameters of distibine complexes are summarized in Table I. 

A general reaction of binuclear distibine complexes is the fission of the Sb-Sb bond and transformation of the R2Sb-SbR2 into a R2Sb groups. 

Disiloxane, tetramesityl-, 3,206 Disproportionation iridium catalysts, 4,1159 Dissolution nuclear fuels, 6, 927 Distannene, 3,217 Distannoxane, 1,3-dichloro-, 3,207 Distibine, tetraphenyl-, 2,1008 Distibines, 2,1008 Disulfido ligands metal complexes, 2,531-540, 553 bonding, 2, 539 electron transfer, 2, 537 intramolecular redox reactions, 2,537 reactions, 2, 537... 

Distibines react as monodentate (type 5) or bridging bidentate (type 6) ligands through donation of the lone pairs of electrons to main group or transition metal centers. Fission of the Sb-Sb bond leads to complexes with bridging R2Sb ligands (type 7, 8 and 9) (Scheme 3). 

Fission of the Sb-Sb bond is even more facile in the distibine-group 13 element complexes and with migration of an alkyl group four- and six-membered heterocycles (type 7 and 8) are formed.76,82... 

In these mixtures the catena-tvistibines are by far the most abundant chain species and even under favorable conditions [excess of cyc/6>-(RSb) ] the caten -tetrastibines form only as minor components. Nevertheless, recently the selective extraction and stabilization of these tetrastibines in the coordination sphere of a transition metal carbonyl complex was achieved by reacting mixtures of distibines and cyclostibines with... 

Diels-Alder reactions, 160-161, 163 Dissociation enthalpy, 229-232, 236, 237, 247 Distibines, 251, 253, 254, 263-265 adducts, 252-255 ligands, 99-106, 124, 125 Dmap-stabilized monomers, 276-291 Dodecatrienediyl-Ni11 complex, 169,... 

A large number of nickel(II) complexes with bidentate tertiary phosphines and arsines have been prepared and characterized since the initial reports on o-phenylenebisdimethylarsine and 1,2-bisdiphenylphosphinoethane (Table 64 XVIII, III) by Chatt and Mann,1267 and Wymore and Bailar126 respectively. The most common diphosphines, diarsines, distibines and mixed donor ligands are collected in Table 64 and selected nickel(II) complexes are reported in Table 65. 

Distibines fall lowest in the spectrochemical series P2 > As2 > St>2,1529 a result which corresponds with the electronic spectra data for the monodentate series PEt3, AsEt3, SbEt3.1530 Mossbauer spectroscopy is a useful method for platinum stibine complexes. Coordination of the stibine causes a large increase in isomer shift and a decrease in quadrupole coupling constant in the 121Sb spectrum, as expected for the formation of a donor bond.1531... 

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