M. Monduzzi , A. Lai , G. Saba , M. Casu , G. Crisponi
{"title":"C-13 magnetic relaxation rates and H-1 and C-13 paramagnetic shifts of Co(II) complex of dopamine","authors":"M. Monduzzi , A. Lai , G. Saba , M. Casu , G. Crisponi","doi":"10.1016/0378-4487(82)80056-3","DOIUrl":null,"url":null,"abstract":"<div><p>The importance of unpaired spin distribution in the Co(II)-Dopamine complex in aqueous solution, was investigated. From the analysis of the H-1 and C-13 isotropic shifts and with the aid of an INDO M.O. calculation on a dopamine radical a prevalent σ-type delocalization mechanism of the spin density was evidentiated, even if a contribution from π-electrons cannot be completely excluded.</p><p>The analysis of the spin-lattice relaxation rates revealed the importance of ligand-centered dipolar interactions. The introduction of the spin densities, calculated from the INDO method, in the modified Solomon-Bloembergen equation, allowed to estimate the correlation time of the complex which can be identified with the electronic relaxation time.</p></div>","PeriodicalId":100049,"journal":{"name":"Advances in Molecular Relaxation and Interaction Processes","volume":"24 4","pages":"Pages 233-244"},"PeriodicalIF":0.0000,"publicationDate":"1982-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0378-4487(82)80056-3","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Molecular Relaxation and Interaction Processes","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0378448782800563","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
The importance of unpaired spin distribution in the Co(II)-Dopamine complex in aqueous solution, was investigated. From the analysis of the H-1 and C-13 isotropic shifts and with the aid of an INDO M.O. calculation on a dopamine radical a prevalent σ-type delocalization mechanism of the spin density was evidentiated, even if a contribution from π-electrons cannot be completely excluded.
The analysis of the spin-lattice relaxation rates revealed the importance of ligand-centered dipolar interactions. The introduction of the spin densities, calculated from the INDO method, in the modified Solomon-Bloembergen equation, allowed to estimate the correlation time of the complex which can be identified with the electronic relaxation time.