The mpz+/mpz Pair as Organic Analogue of the NO+/NO
详细信息 查看全文
详细信息 查看全文
- 作者：Eberhard Waldhö ; r ; Wolfgang Kaim ; José ; A. Olabe ; Leonardo D. Slep ; and Jan Fiedler
- 刊名：Inorganic Chemistry
- 出版年：1997
- 出版时间：July 2, 1997
- 年：1997
- 卷：36
- 期：14
- 页码：2969 - 2974
- 全文大小：187K
- 年卷期：v.36,no.14(July 2, 1997)
- ISSN：1520-510X
文摘
The oxidation and reduction behavior of complexes[(mpz)M(CN)5]2- betweenthe group 8 pentacyanometalates(II) and the N-methylpyrazinium ion mpz+ wasstudied using spectroelectrochemical techniques(UV/vis/NIR,IR, EPR) in nonaqueous and, in part, aqueous media. As a furthersource of information on the electronic structure,we studied the variable solvatochromism of MLCT absorption bands in theprecursor ions[(mpz)M(CN)5]2-.The mpz-centered one-electron reduction showed a tendency forconcomitant loss of cyanide (EC process) toyield ions[(mpz)M(CN)4]2-, thelability increasing in the order M = Os << Ru < Fe. Incontrast to the EPRspectra obtained from reduction withS2O42- in aqueousmedia, which showed no evidence for closempz
/metalassociation, the intra muros electrolysis experiments inDMSO or acetonitrile yielded the following results: TheEPR spectrum that was previously assigned to[(mpz)Fe(CN)5]3- isnow ascribed to[(mpz)Fe(CN)4]2-.Whereasthe dissociatively inert osmium radical complex[(mpz)Os(CN)5]3- isdistinguished by a broad EPR signal witha rather large value giso = 2.0157, the EPRspectrum of[(mpz)Ru(CN)4]3-reveals well-resolved separate couplingwith the 99Ru and 101Ru isotopes innatural abundance. Spectroelectrochemistry and reactivity patternsof thecomplex ions[(mpz)M(CN)5]2- arereminiscent of results for corresponding nitrosyl complexes[(NO)M(CN)5]2-,which suggests that the mpz+/mpz ligandredox pair can function as an organic analogue of theNO+/NO redoxsystem.
/metalassociation, the intra muros electrolysis experiments inDMSO or acetonitrile yielded the following results: TheEPR spectrum that was previously assigned to[(mpz)Fe(CN)5]3- isnow ascribed to[(mpz)Fe(CN)4]2-.Whereasthe dissociatively inert osmium radical complex[(mpz)Os(CN)5]3- isdistinguished by a broad EPR signal witha rather large value giso = 2.0157, the EPRspectrum of[(mpz)Ru(CN)4]3-reveals well-resolved separate couplingwith the 99Ru and 101Ru isotopes innatural abundance. Spectroelectrochemistry and reactivity patternsof thecomplex ions[(mpz)M(CN)5]2- arereminiscent of results for corresponding nitrosyl complexes[(NO)M(CN)5]2-,which suggests that the mpz+/mpz ligandredox pair can function as an organic analogue of theNO+/NO redoxsystem.