TY - JOUR

T1 - How intramolecular coordination bonding (ICB) controls the homolysis of the C-ON bond in alkoxyamines

AU - Audran, Gérard

AU - Bagryanskaya, Elena

AU - Bagryanskaya, Irina

AU - Edeleva, Mariya

AU - Joly, Jean Patrick

AU - Marque, Sylvain R.A.

AU - Iurchenkova, Anna

AU - Kaletina, Polina

AU - Cherkasov, Sergey

AU - Hai, Tung To

AU - Tretyakov, Evgeny

AU - Zhivetyeva, Svetlana

N1 - This journal is © The Royal Society of Chemistry.

PY - 2019/8/18

Y1 - 2019/8/18

N2 - Because the C-ON bond homolysis rate constant kd is an essential parameter of alkoxyamine reactivity, it is especially important to tune kd without a major alteration of the structure of the molecule. Recently, several approaches have become known, e.g., protonation of functional groups and formation of metal complexes. In this paper, coordination reactions of [Zn(hfac)2(H2O)2] with a series of new SG1-based alkoxyamines affording complexes with different structures are presented. The kd values of the complexed forms of the alkoxyamines were compared to those of free and protonated ones to reveal the contribution of the electron-withdrawing property and structure stabilization. Together with previously published data, this work provides clues to the design of alkoxyamines that can be effectively activated upon coordination with metal ions. Furthermore, our results provide insight into the mechanism underlying the influence of complexation on the reactivity of alkoxyamines. This led us to describe different types of coordination: Intramolecular in nitroxyl fragment, intramolecular in alkyl fragment, intramolecular between alkyl and nitroxyl fragment, and intermolecular one. All of them exhibit different trends which are dramatically altered by changes in conformation.

AB - Because the C-ON bond homolysis rate constant kd is an essential parameter of alkoxyamine reactivity, it is especially important to tune kd without a major alteration of the structure of the molecule. Recently, several approaches have become known, e.g., protonation of functional groups and formation of metal complexes. In this paper, coordination reactions of [Zn(hfac)2(H2O)2] with a series of new SG1-based alkoxyamines affording complexes with different structures are presented. The kd values of the complexed forms of the alkoxyamines were compared to those of free and protonated ones to reveal the contribution of the electron-withdrawing property and structure stabilization. Together with previously published data, this work provides clues to the design of alkoxyamines that can be effectively activated upon coordination with metal ions. Furthermore, our results provide insight into the mechanism underlying the influence of complexation on the reactivity of alkoxyamines. This led us to describe different types of coordination: Intramolecular in nitroxyl fragment, intramolecular in alkyl fragment, intramolecular between alkyl and nitroxyl fragment, and intermolecular one. All of them exhibit different trends which are dramatically altered by changes in conformation.

KW - NITROXIDE-MEDIATED POLYMERIZATION

KW - FREE-ENERGY RELATIONSHIPS

KW - POLAR

KW - QUATERNIZATION

KW - IMIDAZOLINE

KW - ZINC(II)

KW - FAMILY

KW - AGENTS

UR - http://www.scopus.com/inward/record.url?scp=85071165823&partnerID=8YFLogxK

U2 - 10.1039/c9ra05334d

DO - 10.1039/c9ra05334d

M3 - Article

C2 - 35530086

AN - SCOPUS:85071165823

VL - 9

SP - 25776

EP - 25789

JO - RSC Advances

JF - RSC Advances

SN - 2046-2069

IS - 44

ER -