TY - JOUR

T1 - Cooperative reduction by Ln2+ and Cp∗- ions

T2 - Synthesis and properties of Sm, Eu, and Yb complexes with 3,6-di-tert-butyl-o-benzoquinone

AU - Pushkarevsky, Nikolay A.

AU - Ogienko, Mikhail A.

AU - Smolentsev, Anton I.

AU - Novozhilov, Igor N.

AU - Witt, Alexander

AU - Khusniyarov, Marat M.

AU - Cherkasov, Vladimir K.

AU - Konchenko, Sergey N.

PY - 2016

Y1 - 2016

N2 - The first examples of samarium, europium, and ytterbium complexes with 3,6-di-tert-butyl-o-benzoquinone (3,6-dbbq) in the form of catecholate have been obtained by reactions of the quinone with the corresponding lanthanocenes, (n = 1 or 2) in solution. In the course of the reactions lanthanide ions lose one or two Cp∗ ligands, which take part in reduction of a quinone molecule into a catecholate anion (dbcat, 2-). As a result of the reactions, Sm and Yb clearly yield dimeric complexes [(LnCp∗)2(dbcat)2], where each Ln ion loses one Cp∗ ligand. Eu forms a trimeric complex [(EuCp∗)(Eu·thf)2(dbcat)3], in which one Eu ion is coordinated by one Cp∗ ligand, while two Eu ions have lost all Cp∗ ligands and are coordinated by THF molecules instead. Magnetic properties corroborate the assignment of oxidation states made on the basis of single-crystal X-ray diffraction: all the quinone ligands are present in the catecholate state; both Sm/Yb ions in the dimers are in the +3 oxidation state, whereas the Eu trimer contains two Eu(ii) and one Eu(iii) ions. Cyclovoltammetry studies show the presence of two reversible oxidation waves for all complexes, presumably concerned with the redox transitions of the dbcat ligands.

AB - The first examples of samarium, europium, and ytterbium complexes with 3,6-di-tert-butyl-o-benzoquinone (3,6-dbbq) in the form of catecholate have been obtained by reactions of the quinone with the corresponding lanthanocenes, (n = 1 or 2) in solution. In the course of the reactions lanthanide ions lose one or two Cp∗ ligands, which take part in reduction of a quinone molecule into a catecholate anion (dbcat, 2-). As a result of the reactions, Sm and Yb clearly yield dimeric complexes [(LnCp∗)2(dbcat)2], where each Ln ion loses one Cp∗ ligand. Eu forms a trimeric complex [(EuCp∗)(Eu·thf)2(dbcat)3], in which one Eu ion is coordinated by one Cp∗ ligand, while two Eu ions have lost all Cp∗ ligands and are coordinated by THF molecules instead. Magnetic properties corroborate the assignment of oxidation states made on the basis of single-crystal X-ray diffraction: all the quinone ligands are present in the catecholate state; both Sm/Yb ions in the dimers are in the +3 oxidation state, whereas the Eu trimer contains two Eu(ii) and one Eu(iii) ions. Cyclovoltammetry studies show the presence of two reversible oxidation waves for all complexes, presumably concerned with the redox transitions of the dbcat ligands.

UR - http://www.scopus.com/inward/record.url?scp=84953911781&partnerID=8YFLogxK

U2 - 10.1039/c5dt03573b

DO - 10.1039/c5dt03573b

M3 - Article

AN - SCOPUS:84953911781

VL - 45

SP - 1269

EP - 1278

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1477-9226

IS - 3

ER -