Unconventional multiple bonds: coordination compounds of unstable Vth main group ligands

Abstract

-Phosphinidene-, arsinidene-and stibinidene-complexes LnMX(R)__ MLn (X = P, As, Sb) contain the main group center X in a tngonally planar environment. The properties of these species are dominated by strong backbonding from filled metal orbitals at the 16 electron groups LnM into the vacant p orbital of the sextett species R-X. The synthesis and properties of LnMX(R)MLn species as well as their chemical interrelation to compounds containing R-X=X-R or IXEXI ligands will be reported.

Synthesis, structure and reactivity of complexes containing a transition metal–bismuth bond

“…This compound contains three carbonylbridged Fe-Fe bonds, and consists of an Fe 3 Bi tetrahedral core with an overall symmetry of C 3v . The Fe-Bi and Fe-Fe bond lengths are comparable to those in systems which have less potential strain [68,84], and the interbond angles are close to the ideal 60 • expected for a regular tetrahedron. This formation of a stable closo-cluster compound highlights the utility of the bridged species as precursors for further cluster chemistry.…”

“…The Cp derivative is essentially monomeric, although the molecules weakly associate to form an infinite spiral chain structure [65]. The dimanganese species has been used to demonstrate the differing reactivity of the so called "bismuthinidenes" with other main group "inidine" compounds, such as those of arsenic and antimony [68]. In the latter examples, the inidene species acts as a Lewis acid towards phosphines, forming stable, isolable adducts [69].…”

Structural chemistry of transition metal complexes containing arsenic-arsenic bonds

“…The main product of the reaction of Re2CO101 is j[cyc(o-(MeAs)7(As)Re(CO)4]Re2(CO)6} (7),24 containing a 03 nine-membered As8Re ring coordinated to two Re(CO)3 groups possessing an overall heavy-atom, trishomocubane structure. Close inspection of the figure for 7…”

Sterically protected organophosphorus compounds in low co-ordination states

“…Phosphaalkynes are phosphorus analogues of nitriles and their chemistry has been developed not only as ligands of transition metal complexes, but also as a building block for further interesting phosphorus-containing heterocyclic compounds. 84-87 The 2,4,6tri-tert-butylphenyl derivative 34 has been prepared by the two different methods, by the elimination of a siloxane from phosphaalkenes 88, 89 and by the 1,2-aryl migration from phosphorus to carbon, which can be considered as a phosphorus version of the Fritsch-Buttenberg-Wiechell reaction (FBW reaction) of E-28, as shown in equation (17). 80, 90 In contrast, the isomer Z-28 did not form phosphaalkyne, indicating that some stereoelectronic effect might be operating during this FBW reaction, as has been postulated by Köbrich and Trapp 91 for the original FBW reactions.…”