Optical absorption and ESR spectra of monomeric rhodium(II) tetraphenylporphyrin in 2-methyltetrahydrofuran solution at 77 K

Hoshino, Mikio; Yasufuku, Katsutoshi; Konishi, Shiro; Imamura, Masashi

doi:10.1021/ic00181a040

Cited by 22 publications

(8 citation statements)

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“…The spectrum of the starting Rh(III) has undergone changes indicating that I - has been replaced by PEt 3 as axial ligand. The spectrum obtained after electrolysis at wave 1 is similar to, albeit not identical, the spectrum previously described of a photogenerated TPPRh(II) complex …”

Section: Resultssupporting

confidence: 83%

Reductive Electrochemistry of Rhodium Porphyrins. Disproportionation of Intermediary Oxidation States

et al. 1997

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The reduction of rhodium(III) porphyrins in polar aprotic solvents is a two-electron irreversible reaction yielding directly the Rh(I) complex. The cause of this irreversibility is not the metal−metal dimerization of the initially formed Rh(II) complex as believed earlier but rather deligation which generates a secondary Rh(II) species easier to reduce than the starting Rh(III) porphyrin. This is confirmed by the fact that sterically encumbered porphyrins, such as those bearing cross-trans basket-handle superstructures which forbid the approach of two molecules at bonding distance, exhibit the same behavior as simple rhodium porphyrins. The occurrence of such an ECE−disproportionation process, seldom observed in the redox chemistry of metallo-porphyrins or similar complexes, is probably related to the tendency of the rhodium atom to shift out of the porphyrin plane, particularly at the Rh(I) oxidation state. It is remarkable that strong and soft ligands, e.g., tertiary phosphines, annihilate the disproportionation of the rhodium(II) complex.

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Section: Resultssupporting

confidence: 83%

Reductive Electrochemistry of Rhodium Porphyrins. Disproportionation of Intermediary Oxidation States

et al. 1997

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“…How do variations in prolonged exposure and cultural traditions influence the relationship? Among the Japanese, for example, the threat of earthquakes and fire far outdistance crimes in the panoply of fears studied by Japanese scholars (Hoshino, 1982). The matter is further complicated by the several meanings which are accorded the concept of trust, as Barber (1983) notes.…”

Section: Summary and Discussionmentioning

confidence: 99%

Crime as Hazard: Perceptions of Risk and Seriousness*

Meier

Short

1985

Criminology

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The study of crime suffers from an inattention to the social consequences of criminal acts. Conceiving crimes within the larger context of '%hazard, " data are reported on the relative seriousness of conventional and white-collar crimes, as well as other hazards, using a sample of Washington state respondents. The results indicate that there is an inverse relationship between the perceived likelihood of a hazard and its seriousness. Generally, the more immediate the threat of a hazard, such as white-collar crimes, the more serious it is perceived to be. There are also implications from these consequences for perceptions of institutional effectiveness and interpersonal reIationshQs. This suggests that future studies of the consequences of criminaliw, especially white-collar and corporate violations, might be directed toward the notions of risk and, eventually, social trust.It has only been recently that sociologists have begun to examine the social costs of crime-the costs of crime for the social community, the social fabric. While there is seemingly no end to the number of estimates of physical and financial loss from crime, sociologists have failed to develop a conceptual base for determining the impact of crimes on the structure of interpersonal and institutional relationships in a community. This is particularly puzzling because sociologists have long indicated that white-collar crime especially has serious consequences for the sense of trust in communities and shared understandings of appropriate behavior (Sutherland, 1983;Cohen, 1966). This paper reports suggestions and preliminary research for such a conceptualization. CRIME AS HAZARDA hazard is a danger or the cause of some danger. Crime is both like and unlike other hazards. Like other hazards, crimes pose risk to persons, property, and/or moral sensibilities. Victimization from crime is similar to victimization from other hazards, such as natural disasters. In each case, life and/or property are at risk without reasonable expectation of retaliation-in the case of most crimes because the criminals are either not known to their victims or, in any case, because the law prohibits direct retaliatory action. In * We wish to acknowledge the financial assistance of the Social Research Center at Washington State University and National Science Foundation grant SES-8020864. A number of persons were involved in the larger study of which this is a part, but we would like particularly to thank Don Dillman for his advice in constructing the questionnaire. CRIMINOLOGY VOLUME 23 NUMBER 3 1985 389

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“…The low-spin Rh(III) (d6), does not show an ESR signal. Since hyperfine splitting in the EPR spectra depends on the interaction of the electrons with the 4 nitrogen atoms of the porphyrin macro-cycle and the metal center, it can also be used to analyze the strength of interactions of metalloporphyrins (Kadish et al, 1985;Kadish et al, 1993;Hoshino et al, 1984;Nakamura, et al, 2006). As expected, a fresh sample of Rh III (TMPyP) 5+ having the Rh(III) oxidation state was ESR silent under the present experimental conditions.…”

Section: Electron Spin Resonance Studiesmentioning

confidence: 99%

Efficient DNA Cleavage Induced by RhIII(TMPyP)5+ in the Presence of Ascorbic Acid

Gunawardhana¹,

Homi²,

Tabata³

2012

IJC

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The ability of Rh(III) tetrakis-N-methylpyridyl porphyrin, Rh III (TMPyP) 5+ , to interact with and cleave DNA was, investigated by UV-visible, luminescence, circular dichroism (CD), electron spin resonance (ESR) and gel electrophoresis methods in the presence or absence of ascorbic acid. UV-absorption data showed that Rh III (TMPyP) 5+ is capable of interacting with DNA, as indicated by the appearance of a red shift and hypochromicity of the Soret band. The CD data revealed that Rh III (TMPyP) 5+ was capable of binding to DNA via an external binding mode. The Rh III (TMPyP) 5+ showed fluorescence and phosphorescence at room temperature. The phosphorescence increased in the presence of DNA and this could be attributed to the shielding of the metal-porphyrin by DNA. Gel electrophoresis studies revealed that Rh III (TMPyP) 5+ was only able to cleave DNA in the presence of the reducing agent ascorbic acid. ESR data indicated the formation of Rh II (TMPyP) 5+ by reduction of Rh III (TMPyP) 5+ with ascorbic acid. The involvement of Rh(III)/Rh(II) species in catalytic DNA cleavage and a possible DNA cleavage mechanism is discussed.

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Optical absorption and ESR spectra of monomeric rhodium(II) tetraphenylporphyrin in 2-methyltetrahydrofuran solution at 77 K

Cited by 22 publications

References 0 publications

Reductive Electrochemistry of Rhodium Porphyrins. Disproportionation of Intermediary Oxidation States

Reductive Electrochemistry of Rhodium Porphyrins. Disproportionation of Intermediary Oxidation States

Crime as Hazard: Perceptions of Risk and Seriousness*

Efficient DNA Cleavage Induced by RhIII(TMPyP)5+ in the Presence of Ascorbic Acid

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