S-O stretching frequencies

Infrared spectra provide further information as to the nature of the S—O bonds. Sulphoxides have an S—O stretching frequency band in the region of 1035-1070 cm -116 while sulphones have two characteristic stretching frequency bands at 1100-1200cm-1 and at 1300-1400cm 1 due to symmetric (vsym) and asymmetric (vasym) frequencies, respectively17. 

S-N bond cleavage 159 S-O bond lengths 543 Solvated electrons 897, 905 Solvent effects 672 in elimination reactions 772 S-O stretching frequencies 543, 545, 546, 552-555, 560-562 Spiroconjugation 390 Stereoselectivity 779, 789 of cylcoaddition reactions 799 of sulphones 761 Steroids... 

The various sulfinate isomers are usually distinguishable by the S-O stretching frequencies Although O- and 0,0 -sulfinate isomers are generally isolated from SO2 insertion reactions with non-transition and early transition metals such as Ti and Zr for the mid and late transition elements S-sulfinates predominate. However, exceptions exist, e.g. the O-sulfinate compound [Ni(02SCH3)(p3)](BPh4) . Work by Wojcicki and others has proven that many (if not all) SO2 insertions with Mo, Mn, and Re complexes proceed via O-sulfinate intermediates, which can subsequently rearrange to more stable... 

Direct reaction of zirconium and hafnium tetrahalides and bromides with excess DMSO under strictly anhydrous conditions yielded products of composition Zr(Hf)Cl4 9DMSO and Zr(Hf)Br4 lODMSO (482). Attempts to recover the tetrahalides by heating only resulted in the production of tarry residues. The S-O-stretching frequency in these compounds was found to be 960 cm" for the nine-solvate and 920 cm for the 10-solvate, which indicates that the DMSO molecules are oxygen bound. 

The deprotonated tris(ethylenediamine) complexes are, not unexpectedly, nucleophilic. The pale yellow doubly deprotonated complex [Rh(en — H)2(en)]I acts as a nucleophile toward Mel, MeBr, SOClj, SO2CI2, and triply deprotonated [Rh(en — 11)3] is electrophilically attacked by Mel (Scheme 16). The methylated species are air and HjO stable, but while air stable, the BF3 and SO2CI2 adducts hydrolyze rapidly. The low S—O stretching frequencies observed led to the suggested bonding configurations shown in Scheme 16, with the sulfur atoms bonded to two amine nit-... 

Complexes of diphenyl sulfoxide exhibit S—O stretching frequencies ranging from 931 cm for Fe" to 1012cm for Mg". The IR spectra of the metal complexes of tetrahydrothiophene oxide (32) show that the complexes of Co", Ni" and Cu" are O-bonded, while those of the (b) class metal ions Pd" and Pt" are S-bonded. ... 

Analogously, a decrease in the S-O stretching frequency, indicative of oxygen coordination, is observed when dimethyl sulfoxide or tetramethylene sulfoxide is complexed to many metal ions, iodine and phenol, whereas the S-O stretching frequency increases in the palladium complex of dimethyl sulfoxide, compared to free sulfoxide, which suggests sulfur coordination. 

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