Complexes of Urea, Sulfoxides, and Related Compounds

Penland et al. first. studied the infrared spectra of urea complexes to determine whether coordination occurs through nitrogen or oxygen. The electronic structure of urea may be represented by a resonance hybrid of structures 1, 11, and 111, with each contributing roughly an equal amount  

Linkage isomerism was found for the formamidopentamminecobalt (111) [(NHj)5Co(—NHaCHO)] and [(NH3)5Co(-OCHNH2)l Although little difference was found in the v(C=0) region, the N-isomer showed the aldehyde i (CH) at 2700 cm , whereas such a band was not obvious in the O-isomer.  

Wayland and Schramm found the first example of mixed coordination of DMSO in the [Pd(DMSO)4] ion it exhibits two S-bonded p(S=0) at 1150 and 1140 cm , and two O-bonded p(S=0) at 920 and 905 cm . Thus the infrared spectrum is most consistent with a configuration in which two 

Complete assignments on infrared and Raman spectra of trans-Pd(DMSO)2X2 (X =Cl and Br) and their deuterated analogs have been made by Tranquille and Forel. Berney and Weber found the order of p MO) in the [M(DMSO)6l ion to be as follows  

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