A series of bisverdazyl biradicals in which the atoms bearing the greatest spin density are separated by several different aromatic spacer groups has been prepared in order to compare their properties to those of the nonspaced 1,1',5,5'-tetramethy1-6,6'-dioxo-3,3'-bisverdazyl (1). In addition, the 6,6'-dithio derivative (1,1',5,5'-tetramethyl-6,6'-dithio-3,3'-bis (7)) was prepared. Cyclic voltammograms of 1,4-bis(1,5-dimethyl-6-oxo-5-verdazyl)benzene (5) and 2,5-bis(1,5-dimethyl-6-oxo-3-verdazyl)thiophene (6) both show a single two-electron oxidation near 700 mV. In contrast 1, 7, and 1,3-bis(1,5-dimethyl-6-oxo-3-verdazyl)benzene (4) display two one-electron oxidation waves, with the first oxidative wave appearing also near 700 mV. The absorption spectrum of each of these biradicals was red-shifted from the maximum observed for 1. Biradicals 4, 5, and 6 exhibited linear Curie plots, although a curved Curie plot was observed for 7 with J = 560 cm(-1).
A series of bisverdazyl biradicals in which the atoms bearing the greatest spin density are separated by several different aromatic spacer groups has been prepared in order to compare their properties to those of the nonspaced 1,1',5,5'-tetramethy1-6,6'-dioxo-3,3'-bisverdazyl (1). In addition, the 6,6'-dithio derivative (1,1',5,5'-tetramethyl-6,6'-dithio-3,3'-bis (7)) was prepared. Cyclic voltammograms of 1,4-bis(1,5-dimethyl-6-oxo-5-verdazyl)benzene (5) and 2,5-bis(1,5-dimethyl-6-oxo-3-verdazyl)thiophene (6) both show a single two-electron oxidation near 700 mV. In contrast 1, 7, and 1,3-bis(1,5-dimethyl-6-oxo-3-verdazyl)benzene (4) display two one-electron oxidation waves, with the first oxidative wave appearing also near 700 mV. The absorption spectrum of each of these biradicals was red-shifted from the maximum observed for 1. Biradicals 4, 5, and 6 exhibited linear Curie plots, although a curved Curie plot was observed for 7 with J = 560 cm(-1).
Neugebauer, Franz Alfred; Fischer, Hans; Siegel, Rolf, Chemische Berichte, 1983, vol. 116, # 10, p. 3461 - 3481
作者:Neugebauer, Franz Alfred、Fischer, Hans、Siegel, Rolf、Krieger, Claus
DOI:——
日期:——
NEUGEBAUER, F. A.;FISCHER, H.;SIEGEL, R.;KRIEGER, C., CHEM. BER., 1983, 116, N 10, 3461-3481
作者:NEUGEBAUER, F. A.、FISCHER, H.、SIEGEL, R.、KRIEGER, C.
DOI:——
日期:——
Electronic Interactions in Verdazyl Biradicals
作者:Rosario M. Fico、Michael F. Hay、Scott Reese、Steve Hammond、Elizabeth Lambert、Marye Anne Fox
DOI:10.1021/jo990962s
日期:1999.12.1
A series of bisverdazyl biradicals in which the atoms bearing the greatest spin density are separated by several different aromatic spacer groups has been prepared in order to compare their properties to those of the nonspaced 1,1',5,5'-tetramethy1-6,6'-dioxo-3,3'-bisverdazyl (1). In addition, the 6,6'-dithio derivative (1,1',5,5'-tetramethyl-6,6'-dithio-3,3'-bis (7)) was prepared. Cyclic voltammograms of 1,4-bis(1,5-dimethyl-6-oxo-5-verdazyl)benzene (5) and 2,5-bis(1,5-dimethyl-6-oxo-3-verdazyl)thiophene (6) both show a single two-electron oxidation near 700 mV. In contrast 1, 7, and 1,3-bis(1,5-dimethyl-6-oxo-3-verdazyl)benzene (4) display two one-electron oxidation waves, with the first oxidative wave appearing also near 700 mV. The absorption spectrum of each of these biradicals was red-shifted from the maximum observed for 1. Biradicals 4, 5, and 6 exhibited linear Curie plots, although a curved Curie plot was observed for 7 with J = 560 cm(-1).