Transition metal complexes sulfur dioxide

Phosphoryl fluoride reacts as a base and, with BF , AsF5, and SbF5, oxygen-bridged 1 1 adducts are produced (88, 89). In liquid sulfur dioxide POF3 is weakly basic and it was in such a medium that the first transition-metal complex of this oxide fluoride, [Mn(OPF j)4]2v[AsF6l2, was produced in 1979 via the intermediate Mn(S02)v 2 AsFe]2 (90). 

Stoichiometric reaction of sulfur dioxide with transition metal complexes... 

Cook RL, MacDuff RC, Sammels AF (1989) Organophosphine transition metal complexes as selective surfaces for the reversible detection of sulfur dioxide with piezoelectric crystal sensors. Anal Chim Acta 217 101-109 D Amico A, Verona E (1989) SAW sensors. Sens Actuators 17 55-66... 

Ryan RR, Kubas GJ, Moody DC, Eller PG (1981) Structure and Bonding of Transition Metal-Sulfur Dioxide Complexes. 46 47-100... 

This chapter is concerned entirely with the insertion of carbon monoxide into transition metal-carbon cr-bonds. Sulfur dioxide insertion 154, 239), also common among transition metal-carbon complexes, will be treated in a complementary review, which is to appear later. Subject to the restrictions given at the beginning of Section VI, an attempt has been made at a complete literature coverage of the insertion of CO. Particular emphasis focuses on recent results, especially those of a kinetic and stereochemical nature. 

Palladium(II) complexes possessing bidentate ligands are known to efficiently catalyze the copolymerization of olefins with carbon monoxide to form polyketones.594-596 Sulfur dioxide is an attractive monomer for catalytic copolymerizations with olefins since S02, like CO, is known to undergo facile insertion reactions into a variety of transition metal-alkyl bonds. Indeed, Drent has patented alternating copolymerization of ethylene with S02 using various palladium(II) complexes.597 In 1998, Sen and coworkers also reported that [(dppp)PdMe(NCMe)]BF4 was an effective catalyst for the copolymerization of S02 with ethylene, propylene, and cyclopentene.598 There is a report of the insertion reactions of S02 into PdII-methyl bonds and the attempted spectroscopic detection of the copolymerization of ethylene and S02.599... 

The S02 molecule has unshared pairs of electrons on both the sulfur and oxygen atoms. As a result, it forms numerous complexes with transitions metals in which it is known to attach in several ways. These include bonding through the sulfur atom, through an oxygen atom, by both oxygen atoms, and various bridging schemes. In most cases, the complexes involve soft metals in low oxidation states. Another important reaction of sulfur dioxide is known as the insertion reaction, in which it is placed... 

Sulfur dioxide also forms complexes with a number of transition metal species (Section 12-16). 

REACTIONS OF SULFUR DIOXIDE WITH o-ALLYL, PROPARGYL, CYCLOPROPYL, AND CYCLOPROPYLMETHYL COMPLEXES OF TRANSITION METALS... 

Structure and Bonding of Transition Metal-Sulfur Dioxide Complexes ... 

An excellent review entitled Sulfur Dioxide Complexes of the Platinum Metals has recently appeared which, in addition to the subject impUed by the title, addresses the electronic structure of SO2 and its bonding to metal complexes. The present work attempts a more comprehensive review of the structure and bonding of transition metal-SO2 complexes, with particular emphasis on results which have appeared since the previous review. 

Although the study of sulfur dioxide-transition metal coordination chemistry is an area of relatively recent intensive pursuit, structural information now spans a large number of stereochemically distinct coordination situations. The types of M-SO2 binding which have been identified, excluding insertion compounds and compounds containing SO2 bridging metal centers, are shown in Fig. 1. Several examples of complexes containing each type... 

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