Irene Bonastre-Sabater, Alberto Lopera, Álvaro Martínez-Camarena, Salvador Blasco, Antonio Doménech-Carbó, Hermas Jimenez, Begoña Verdejo, Enrique García-España, Maria Paz Clares
{"title":"在 [1+1] 缩合偶氮环中,外向或内向 1H 吡唑金属配位受多胺链长度的调节。具有显著 SOD 活性的双核配合物","authors":"Irene Bonastre-Sabater, Alberto Lopera, Álvaro Martínez-Camarena, Salvador Blasco, Antonio Doménech-Carbó, Hermas Jimenez, Begoña Verdejo, Enrique García-España, Maria Paz Clares","doi":"10.1039/d4dt01236d","DOIUrl":null,"url":null,"abstract":"The Cu2+ complexes of three [1+1] azacyclophane macrocycles having the 1H-pyrazole ring as spacer and the pentaamine 1,5,8,11,15-pentaazadecane (L1) or the hexaamines 1,5,8,12,15,19-hexaazanonadecane (L2) and 1,5,9,13,17,21-hexaazaheneicosane (L3) as bridges show endo coordination of the pyrazolate bridge giving rise to discrete monomeric species. Previously reported pyrazolacyclophanes evidenced, however, exo-coordination with formation of dimeric species of 2:2, 3:2 or even 4:2 Cu2+:L stoichiometry. The complexes have been characterized in solution using potentiometric studies, UV-Vis spectroscopy, paramagnetic NMR, cyclic voltammetry and mass spectrometry. The measurements show that all three ligands have as many protonation steps in water as secondary amines are in the bridge, while they are able to form both mono- and binuclear Cu2+ species. The crystal structures of the complexes [Cu(HL1)Br]Br(1+x)(ClO4)(1-x)·yH2O (1) and [Cu2(H-1L2)Cl(ClO4)](ClO4)·H2O·C2H5OH (2) have been solved by X-ray diffraction studies. In 1 the metal ion lies at one side of the macrocyclic cavity being coordinated by one nitrogen of the pyrazolate moiety and the three consecutive nitrogen atoms of the polyamine bridge. The other nitrogen of the pyrazole ring is hydrogen-bonded to an amine group. In 2 the two metal ions are interconnected by a pyrazolate bis(monodentate) moiety and complete their coordination spheres with three amines and either a bromide or a perchlorate anion, which occupy the axial positions of distorted square pyramid geometries. Paramagnetic NMR studies of the binuclear complexes confirm the coordination pattern observed in the crystal structures. Cyclic voltamperommetry data show potentials within the adequate range to exhibit superoxide dismutase (SOD) activity. The IC50 values calculated by McCord-Fridovich enzymatic assays show that the binuclear Cu2+ complexes of L2 and L3 have SOD activities that rank amongst the highest ones so far reported","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":3.5000,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Exo- or Endo- 1H-Pyrazole Metal Coordination Modulated by Polyamine Chain length in [1+1] Condensation Azamacrocycles. Binuclear Complexes with Remarkable SOD activity\",\"authors\":\"Irene Bonastre-Sabater, Alberto Lopera, Álvaro Martínez-Camarena, Salvador Blasco, Antonio Doménech-Carbó, Hermas Jimenez, Begoña Verdejo, Enrique García-España, Maria Paz Clares\",\"doi\":\"10.1039/d4dt01236d\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The Cu2+ complexes of three [1+1] azacyclophane macrocycles having the 1H-pyrazole ring as spacer and the pentaamine 1,5,8,11,15-pentaazadecane (L1) or the hexaamines 1,5,8,12,15,19-hexaazanonadecane (L2) and 1,5,9,13,17,21-hexaazaheneicosane (L3) as bridges show endo coordination of the pyrazolate bridge giving rise to discrete monomeric species. Previously reported pyrazolacyclophanes evidenced, however, exo-coordination with formation of dimeric species of 2:2, 3:2 or even 4:2 Cu2+:L stoichiometry. The complexes have been characterized in solution using potentiometric studies, UV-Vis spectroscopy, paramagnetic NMR, cyclic voltammetry and mass spectrometry. The measurements show that all three ligands have as many protonation steps in water as secondary amines are in the bridge, while they are able to form both mono- and binuclear Cu2+ species. The crystal structures of the complexes [Cu(HL1)Br]Br(1+x)(ClO4)(1-x)·yH2O (1) and [Cu2(H-1L2)Cl(ClO4)](ClO4)·H2O·C2H5OH (2) have been solved by X-ray diffraction studies. In 1 the metal ion lies at one side of the macrocyclic cavity being coordinated by one nitrogen of the pyrazolate moiety and the three consecutive nitrogen atoms of the polyamine bridge. The other nitrogen of the pyrazole ring is hydrogen-bonded to an amine group. In 2 the two metal ions are interconnected by a pyrazolate bis(monodentate) moiety and complete their coordination spheres with three amines and either a bromide or a perchlorate anion, which occupy the axial positions of distorted square pyramid geometries. Paramagnetic NMR studies of the binuclear complexes confirm the coordination pattern observed in the crystal structures. Cyclic voltamperommetry data show potentials within the adequate range to exhibit superoxide dismutase (SOD) activity. The IC50 values calculated by McCord-Fridovich enzymatic assays show that the binuclear Cu2+ complexes of L2 and L3 have SOD activities that rank amongst the highest ones so far reported\",\"PeriodicalId\":71,\"journal\":{\"name\":\"Dalton Transactions\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-07-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Dalton Transactions\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://doi.org/10.1039/d4dt01236d\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Dalton Transactions","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d4dt01236d","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
Exo- or Endo- 1H-Pyrazole Metal Coordination Modulated by Polyamine Chain length in [1+1] Condensation Azamacrocycles. Binuclear Complexes with Remarkable SOD activity
The Cu2+ complexes of three [1+1] azacyclophane macrocycles having the 1H-pyrazole ring as spacer and the pentaamine 1,5,8,11,15-pentaazadecane (L1) or the hexaamines 1,5,8,12,15,19-hexaazanonadecane (L2) and 1,5,9,13,17,21-hexaazaheneicosane (L3) as bridges show endo coordination of the pyrazolate bridge giving rise to discrete monomeric species. Previously reported pyrazolacyclophanes evidenced, however, exo-coordination with formation of dimeric species of 2:2, 3:2 or even 4:2 Cu2+:L stoichiometry. The complexes have been characterized in solution using potentiometric studies, UV-Vis spectroscopy, paramagnetic NMR, cyclic voltammetry and mass spectrometry. The measurements show that all three ligands have as many protonation steps in water as secondary amines are in the bridge, while they are able to form both mono- and binuclear Cu2+ species. The crystal structures of the complexes [Cu(HL1)Br]Br(1+x)(ClO4)(1-x)·yH2O (1) and [Cu2(H-1L2)Cl(ClO4)](ClO4)·H2O·C2H5OH (2) have been solved by X-ray diffraction studies. In 1 the metal ion lies at one side of the macrocyclic cavity being coordinated by one nitrogen of the pyrazolate moiety and the three consecutive nitrogen atoms of the polyamine bridge. The other nitrogen of the pyrazole ring is hydrogen-bonded to an amine group. In 2 the two metal ions are interconnected by a pyrazolate bis(monodentate) moiety and complete their coordination spheres with three amines and either a bromide or a perchlorate anion, which occupy the axial positions of distorted square pyramid geometries. Paramagnetic NMR studies of the binuclear complexes confirm the coordination pattern observed in the crystal structures. Cyclic voltamperommetry data show potentials within the adequate range to exhibit superoxide dismutase (SOD) activity. The IC50 values calculated by McCord-Fridovich enzymatic assays show that the binuclear Cu2+ complexes of L2 and L3 have SOD activities that rank amongst the highest ones so far reported
期刊介绍:
Dalton Transactions is a journal for all areas of inorganic chemistry, which encompasses the organometallic, bioinorganic and materials chemistry of the elements, with applications including synthesis, catalysis, energy conversion/storage, electrical devices and medicine. Dalton Transactions welcomes high-quality, original submissions in all of these areas and more, where the advancement of knowledge in inorganic chemistry is significant.