{"title":"镍(II)位阻3N给体配合物作为槲皮素-2,4-双加氧酶的模型:末端胺取代基对双加氧反应活性的影响","authors":"Devaraj Karthickram, Nattamai Bhuvanesh, Karuppasamy Sundaravel","doi":"10.1002/ejic.202400547","DOIUrl":null,"url":null,"abstract":"<p>Four mononuclear nickel(II) complexes <b>1</b>–<b>4</b> of terminal nitrogens systematically derivatized diethylenetriamine ligands [<b>L1</b>=<i>N</i><sup><i>1</i></sup>-(cyclohexylmethyl)-<i>N</i><sup><i>2</i></sup>-(2-((cyclohexyl- methyl)amino)ethyl)ethane-1,2-diamine, <b>L2</b>=<i>N</i><sup><i>1</i></sup>-benzyl-<i>N</i><sup><i>2</i></sup>-(2-(benzylamino)- ethyl)ethane-1,2-diamine, <b>L3</b>=<i>N</i><sup><i>1</i></sup>-phenethyl-<i>N</i><sup><i>2</i></sup>-(2-(phenethylamino)ethyl)ethane-1,2-diamine and <b>L4</b>=<i>N</i><sup><i>1</i></sup>-(naphthalen-1-ylmethyl)-<i>N</i><sup><i>2</i></sup>-(2-((naphthalen-1-ylmethyl)amino)ethyl)ethane-1,2-diamine] and their nickel(II)-flavonolate adducts <b>1 a</b>–<b>4 a</b> have been synthesized as biomimetic models for nickel(II)-containing quercetin-2,4-dioxygenase. XRD analysis of complex <b>1</b> reveals a distorted octahedral coordination environment around nickel(II) with NiN<sub>3</sub>Cl<sub>2</sub>O chromophore. The <i>E</i><sub>pa</sub> values (+0.903 V for <b>3 a</b><+0.931 V for <b>1 a</b><+0.941 V for <b>4 a</b><+0.949 V for <b>2 a</b>) in DMF attribute the increase in Lewis acidity of Ni(II) centre in the adducts with concomitant decrease in the extend of π-back bonding from Ni(II)-to-fla<sup>−</sup> as influenced by the nature of terminal <i>N</i><sub>cycloalkyl/aryl</sub> substituents. Upon exposure to O<sub>2</sub>, all the adducts in DMF at 70 °C decompose the bound fla<sup>−</sup> into their ring-opened products at reasonable rate constant values (1.8–2.3×10<sup>−3</sup> s<sup>−1</sup>). The adduct <b>3 a</b> with an additional −CH<sub>2</sub> spacer makes the phenyl ring more dangling than that in <b>2 a</b>, renders less steric crowding at terminal nitrogen thereby enhance the Ni(II)→flavonolate π-backdonation and rate of dioxygenation. The formation of flavonoxy radical during the dioxygenative degradation pathway is confirmed by adding free-radical scavenger TEMPO.</p>","PeriodicalId":38,"journal":{"name":"European Journal of Inorganic Chemistry","volume":"27 36","pages":""},"PeriodicalIF":2.0000,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Nickel(II) Complexes of Sterically Hindered 3N Donor Ligands as Models for Quercetin-2,4-Dioxygenase: Impact of Terminal Amine Substituent on Dioxygenolysis Reactivity\",\"authors\":\"Devaraj Karthickram, Nattamai Bhuvanesh, Karuppasamy Sundaravel\",\"doi\":\"10.1002/ejic.202400547\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Four mononuclear nickel(II) complexes <b>1</b>–<b>4</b> of terminal nitrogens systematically derivatized diethylenetriamine ligands [<b>L1</b>=<i>N</i><sup><i>1</i></sup>-(cyclohexylmethyl)-<i>N</i><sup><i>2</i></sup>-(2-((cyclohexyl- methyl)amino)ethyl)ethane-1,2-diamine, <b>L2</b>=<i>N</i><sup><i>1</i></sup>-benzyl-<i>N</i><sup><i>2</i></sup>-(2-(benzylamino)- ethyl)ethane-1,2-diamine, <b>L3</b>=<i>N</i><sup><i>1</i></sup>-phenethyl-<i>N</i><sup><i>2</i></sup>-(2-(phenethylamino)ethyl)ethane-1,2-diamine and <b>L4</b>=<i>N</i><sup><i>1</i></sup>-(naphthalen-1-ylmethyl)-<i>N</i><sup><i>2</i></sup>-(2-((naphthalen-1-ylmethyl)amino)ethyl)ethane-1,2-diamine] and their nickel(II)-flavonolate adducts <b>1 a</b>–<b>4 a</b> have been synthesized as biomimetic models for nickel(II)-containing quercetin-2,4-dioxygenase. XRD analysis of complex <b>1</b> reveals a distorted octahedral coordination environment around nickel(II) with NiN<sub>3</sub>Cl<sub>2</sub>O chromophore. The <i>E</i><sub>pa</sub> values (+0.903 V for <b>3 a</b><+0.931 V for <b>1 a</b><+0.941 V for <b>4 a</b><+0.949 V for <b>2 a</b>) in DMF attribute the increase in Lewis acidity of Ni(II) centre in the adducts with concomitant decrease in the extend of π-back bonding from Ni(II)-to-fla<sup>−</sup> as influenced by the nature of terminal <i>N</i><sub>cycloalkyl/aryl</sub> substituents. Upon exposure to O<sub>2</sub>, all the adducts in DMF at 70 °C decompose the bound fla<sup>−</sup> into their ring-opened products at reasonable rate constant values (1.8–2.3×10<sup>−3</sup> s<sup>−1</sup>). The adduct <b>3 a</b> with an additional −CH<sub>2</sub> spacer makes the phenyl ring more dangling than that in <b>2 a</b>, renders less steric crowding at terminal nitrogen thereby enhance the Ni(II)→flavonolate π-backdonation and rate of dioxygenation. The formation of flavonoxy radical during the dioxygenative degradation pathway is confirmed by adding free-radical scavenger TEMPO.</p>\",\"PeriodicalId\":38,\"journal\":{\"name\":\"European Journal of Inorganic Chemistry\",\"volume\":\"27 36\",\"pages\":\"\"},\"PeriodicalIF\":2.0000,\"publicationDate\":\"2024-11-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"European Journal of Inorganic Chemistry\",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/ejic.202400547\",\"RegionNum\":4,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Inorganic Chemistry","FirstCategoryId":"1","ListUrlMain":"https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/ejic.202400547","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
Nickel(II) Complexes of Sterically Hindered 3N Donor Ligands as Models for Quercetin-2,4-Dioxygenase: Impact of Terminal Amine Substituent on Dioxygenolysis Reactivity
Four mononuclear nickel(II) complexes 1–4 of terminal nitrogens systematically derivatized diethylenetriamine ligands [L1=N1-(cyclohexylmethyl)-N2-(2-((cyclohexyl- methyl)amino)ethyl)ethane-1,2-diamine, L2=N1-benzyl-N2-(2-(benzylamino)- ethyl)ethane-1,2-diamine, L3=N1-phenethyl-N2-(2-(phenethylamino)ethyl)ethane-1,2-diamine and L4=N1-(naphthalen-1-ylmethyl)-N2-(2-((naphthalen-1-ylmethyl)amino)ethyl)ethane-1,2-diamine] and their nickel(II)-flavonolate adducts 1 a–4 a have been synthesized as biomimetic models for nickel(II)-containing quercetin-2,4-dioxygenase. XRD analysis of complex 1 reveals a distorted octahedral coordination environment around nickel(II) with NiN3Cl2O chromophore. The Epa values (+0.903 V for 3 a<+0.931 V for 1 a<+0.941 V for 4 a<+0.949 V for 2 a) in DMF attribute the increase in Lewis acidity of Ni(II) centre in the adducts with concomitant decrease in the extend of π-back bonding from Ni(II)-to-fla− as influenced by the nature of terminal Ncycloalkyl/aryl substituents. Upon exposure to O2, all the adducts in DMF at 70 °C decompose the bound fla− into their ring-opened products at reasonable rate constant values (1.8–2.3×10−3 s−1). The adduct 3 a with an additional −CH2 spacer makes the phenyl ring more dangling than that in 2 a, renders less steric crowding at terminal nitrogen thereby enhance the Ni(II)→flavonolate π-backdonation and rate of dioxygenation. The formation of flavonoxy radical during the dioxygenative degradation pathway is confirmed by adding free-radical scavenger TEMPO.
期刊介绍:
The European Journal of Inorganic Chemistry (2019 ISI Impact Factor: 2.529) publishes Full Papers, Communications, and Minireviews from the entire spectrum of inorganic, organometallic, bioinorganic, and solid-state chemistry. It is published on behalf of Chemistry Europe, an association of 16 European chemical societies.
The following journals have been merged to form the two leading journals, European Journal of Inorganic Chemistry and European Journal of Organic Chemistry:
Chemische Berichte
Bulletin des Sociétés Chimiques Belges
Bulletin de la Société Chimique de France
Gazzetta Chimica Italiana
Recueil des Travaux Chimiques des Pays-Bas
Anales de Química
Chimika Chronika
Revista Portuguesa de Química
ACH—Models in Chemistry
Polish Journal of Chemistry
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