Dithioacid complexes

The reaction of (CH3XCF3)3PN(CH3)2 with CS2 proceeds with CS2 insertion into the P-N bond and formation of the (CH3XCF3)3F(Me2Dtc) compound (S90). Very little is known about the chemistry of the xanthate or dithioacid complexes of the Group V elements. The P(EtXant)3 has been reported (410). The IR spectrum of this molecule and those of the corresponding As(III) and Sb(III) compounds show a monotonic decrease of the C—O vibration around 1200 cm 1 (by 7 cm-1 intervals) from P to Bi (635). 

Xonthates and Dithioacid Complexes. Various facets of the chemistry of the Zn(RXant)2 complexes have been explored (153). In recent years the interactions of these complexes with bases such as Py, DMSO, and o-phen have been studied to a considerable extent (331,332,346). The infrared spectra also have been reported (625). 

By contrast to the R2Dtc complexes, which show low-intensity d-d absorption bands, the dithioacid complexes show six bands between 11 and 25 kK (e, 2000—14,000) that have been assigned to charge-transfer absorptions (520). Electrochemical studies on the Mo(RDta)4 complexes for R = tolyl and naphthoyl groups have been reported (482). More recent electrochemical studies... 

Differences in E% values between thioxanthate complexes and dithioacid complexes for equivalent processes have been related to the superior electron-... 

A ligand field model has been used for the interpretation of the magnetic behavior of the Mo(R2Dtc)4 complexes (485). Extended Hiickel calculations compare the electron-donating characteristics of the dithiocarbamate ligand to other 1,1-dithio chelates. This calculation concluded that (1) there is more metal character in the lowest unoccupied MO in the dithiocarbamate complexes, and (2) there is more ligand character in the lowest unoccupied MO in the dithioacid complexes (485). This seems to be in agreement with the electronic spectra. 

The perthiopivalate ligand (r-BuDtaS) was obtained (246) essentially by the original synthetic procedure used for the synthesis of aryl dithioacids complexes (156). The electronic spectra of Ni(f-BuDtaS)2, Ni(PhDtaS)2, and Ni(p-MePhDtaS)2 complexes have been discussed (246) (see also Section IV). 

Table 96 Structures Some 1,1-Dithioacid Complexes of Cobalt... 

Table 97 Preparation and Properties of Trialkyl Phosphine Dithioacid Complexes...

Dithioacid complexes of bismuth are numerous (Table 4) and repeat many of the structural motifs of their arsenic and antimony analogues, most notably the very asymmetric coordination ( anisobidentate ), although, as a consequence of the larger bismuth atom, higher coordination numbers are more evident. In the xanthates, seven-coordinate bismuth appears to be favored, although this is achieved in different ways in [Bi(S2COR)3] (R = PhCH2, c-CeHn, Bu ) there are... 

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