Sulfur, bond number

Carbon—Sulfur Cleavage. The carbon—sulfur bond of DMSO is broken in a number of reactions. Attempts to form the DMSO anion by the reaction of DMSO with sodium result in cleavage accompanied by methane evolution (eqs. 10 and 11) (43) ... 

Trialkyl- and triarylarsine sulfides have been prepared by several different methods. The reaction of sulfur with a tertiary arsine, with or without a solvent, gives the sulfides in almost quantitative yields. Another method involves the reaction of hydrogen sulfide with a tertiary arsine oxide, hydroxyhahde, or dihaloarsorane. X-ray diffraction studies of triphenylarsine sulfide [3937-40-4], C gH AsS, show the arsenic to be tetrahedral the arsenic—sulfur bond is a tme double bond (137). Triphenylarsine sulfide and trimethylarsine sulfide [38859-90-4], C H AsS, form a number of coordination compounds with salts of transition elements (138,139). Both trialkyl- and triarylarsine selenides have been reported. The trialkyl compounds have been prepared by refluxing trialkylarsines with selenium powder (140). The preparation of triphenylarsine selenide [65374-39-2], C gH AsSe, from dichlorotriphenylarsorane and hydrogen selenide has been reported (141), but other workers could not dupHcate this work (140). 

The properties of some sulfide minerals can be discussed in a reasonably satisfactory way by assigning one or another of the structures of Table I to the sulfur atoms. For some minerals the ligancy of the sulfur atom is equal to its covalence, and for others it is greater, the bonds then having fractional bond numbers. It is often necessary to assign a hybrid structure to the sulfur atoms. I shall assume that the covalent bonds indicated in Table I always have the normal amount of covalent character, as given by the... 

The sulfur-rich oxides S 0 and S 02 belong to the group of so-called lower oxides of sulfur named after the low oxidation state of the sulfur atom(s) compared to the best known oxide SO2 in which the sulfur is in the oxidation state +4. Sulfur monoxide SO is also a member of this class but is not subject of this review. The blue-green material of composition S2O3 described in the older literature has long been shown to be a mixture of salts with the cations S4 and Ss and polysulfate anions rather than a sulfur oxide [1,2]. Reliable reviews on the complex chemistry of the lower sulfur oxides have been published before [1, 3-6]. The present review deals with those sulfur oxides which contain at least one sulfur-sulfur bond and not more than two oxygen atoms. These species are important intermediates in a number of redox reactions of elemental sulfur and other sulfur compounds. 

The tetradentate ligand forms monomeric square planar complexes. Synthetic and kinetic studies reveal that the coordinated mercapto group may be converted into the coordinated thioether function without breaking the metal-sulfur bond. The nucleophilic power of the coordinated mercapto group exceeds that of RSH, but depends on the metal atom. Bridging protects the sulfur atom from alkylation. In the case of nickel(ll), alkylation is accompanied by expansion of the coordination number of the nickel from 4 to 6. Ligand reactions have led to the synthesis of planar ligands completely cydized about the metal ion. 

A theoretical foundation for understanding these correlations is found in the calculated bulk electronic structures of the first- and second-row TMS. The electronic environment of the metal surrounded by six sulfur atoms in an octahedral configuration was calculated, using the hypotheses that all the sulfides could be represented by this symmetry as an approximation. There are several electronic factors that appear to be related to catalytic activity the orbital occupation of the HOMO (Highest Occupied Molecular Orbital), the degree of covalency of the metal-sulfur bond, and the metal-sulfur bond strength. These factors were incorporated into an activity parameter (A2), which correlates well with the periodic trends (Fig. 16) (74, 75). This parameter is equal to the product of the number of electrons contained in the... 

The bond length in C8 has been determined by microwave spectros-copy to be 1.535 A, which corresponds to bond number 2.4. Another vcb t for th - bend number can be derived from the observed values6 lAi D >.he electric dipole moment. Carbon and sulfur have the electronegativity, and accordingly the dipole moment arises entirely from the uhTerence in the contributions of the two structures... 

The structure is also stabilized by the formation of metal-metal bonds. Each vanadium atom has six copper neighbors at 2.635 A, corresponding to bond number 0.3. Hence each vanadium atom forms four single bonds with the four adjacent sulfur atoms and six one-third bonds wii.h the six adjacent copper atoms. One electron has been... 

List these bonds in order of increasing polarity P-F, S-F, Ga-F, Ge-F (F, fluorine, atomic number g P, phosphorus, atomic number 15 S, sulfur, atomic number 16 Ga, gallium, atomic number 31 Ge, germanium, atomic number 32) ... 

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