Synthesis and structural characterization of amido scorpionate rare earth metals complexes

TY - JOUR

T1 - Synthesis and structural characterization of amido scorpionate rare earth metals complexes

AU - Márquez-Segovia, Isabel

AU - Lara-Sánchez, Agustín

AU - Otero, Antonio

AU - Fernández-Baeza, Juan

AU - Castro-Osma, José Antonio

AU - Sánchez-Barba, Luis F.

AU - Rodríguez, Ana M.

PY - 2014/7/7

Y1 - 2014/7/7

N2 - The reactivity of hybrid scorpionate/cyclopentadienyl ligands in the form of the protio derivatives as a mixture of two regioisomers, namely bpzcpH [1-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl}-1,3-cyclopentadiene and 2-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl}-1,3-cyclopentadiene] and bpztcpH [1-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethyl}-1,3- cyclopentadiene and 2-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethyl}-1,3- cyclopentadiene], with the tris(silylamide) precursors [M{N(SiHMe 2)2}3(thf)x] of rare earth metals (including the group 3 metals scandium and yttrium) is related to the atomic radii of the metal centres. The reaction with the precursor containing the smallest ion, [Sc{N(SiHMe2)2}3(thf)], did not proceed even heating at reflux temperature in toluene. The reaction with the precursors that contain a medium-sized metal ion, i.e., [M{N(SiHMe 2)2}3(thf)2] (M = Y, Lu), proceeded only at high temperature and gave good yields of the silylenediamide-containing derivatives [M{κ2-NN-Me2Si(NSiHMe2) 2}(bpzcp)] (M = Y 1, Lu 2) and [M{κ2-NN-Me 2Si(NSiHMe2)2}(bpztcp)] (M = Y 3, Lu 4) by an double activation of Si-H and Si-N bonds. However, the reaction with the precursors that contained the largest metal ions, i.e., [M{N(SiHMe 2)2}3(thf)2] (M = Nd, Sm), proceeded rapidly at room temperature to afford the bis(silylamide) complexes [M{N(SiHMe2)2}2(bpzcp)] (M = Nd 5, Sm 6) and [M{N(SiHMe2)2}2(bpztcp)] (M = Nd 7, Sm 8). Additionally, the alkyl heteroscorpionate yttrium and lutetium complexes [M(CH2SiMe3)2(NNCp)] (M = Y, Lu) reacted with an excess of HN(SiHMe2)2 to give the mixed alkyl/amide derivatives [M{N(SiHMe2)2}(CH2SiMe 3)(bpzcp)] (M = Y 9, Lu 10) and [M{N(SiHMe2) 2}(CH2SiMe3)(bpztcp)] (M = Y 11, Lu 12). The structures of the complexes were determined by spectroscopic methods and the X-ray crystal structures of 1, 3 and 5 were also established.

AB - The reactivity of hybrid scorpionate/cyclopentadienyl ligands in the form of the protio derivatives as a mixture of two regioisomers, namely bpzcpH [1-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl}-1,3-cyclopentadiene and 2-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl}-1,3-cyclopentadiene] and bpztcpH [1-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethyl}-1,3- cyclopentadiene and 2-{2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethyl}-1,3- cyclopentadiene], with the tris(silylamide) precursors [M{N(SiHMe 2)2}3(thf)x] of rare earth metals (including the group 3 metals scandium and yttrium) is related to the atomic radii of the metal centres. The reaction with the precursor containing the smallest ion, [Sc{N(SiHMe2)2}3(thf)], did not proceed even heating at reflux temperature in toluene. The reaction with the precursors that contain a medium-sized metal ion, i.e., [M{N(SiHMe 2)2}3(thf)2] (M = Y, Lu), proceeded only at high temperature and gave good yields of the silylenediamide-containing derivatives [M{κ2-NN-Me2Si(NSiHMe2) 2}(bpzcp)] (M = Y 1, Lu 2) and [M{κ2-NN-Me 2Si(NSiHMe2)2}(bpztcp)] (M = Y 3, Lu 4) by an double activation of Si-H and Si-N bonds. However, the reaction with the precursors that contained the largest metal ions, i.e., [M{N(SiHMe 2)2}3(thf)2] (M = Nd, Sm), proceeded rapidly at room temperature to afford the bis(silylamide) complexes [M{N(SiHMe2)2}2(bpzcp)] (M = Nd 5, Sm 6) and [M{N(SiHMe2)2}2(bpztcp)] (M = Nd 7, Sm 8). Additionally, the alkyl heteroscorpionate yttrium and lutetium complexes [M(CH2SiMe3)2(NNCp)] (M = Y, Lu) reacted with an excess of HN(SiHMe2)2 to give the mixed alkyl/amide derivatives [M{N(SiHMe2)2}(CH2SiMe 3)(bpzcp)] (M = Y 9, Lu 10) and [M{N(SiHMe2) 2}(CH2SiMe3)(bpztcp)] (M = Y 11, Lu 12). The structures of the complexes were determined by spectroscopic methods and the X-ray crystal structures of 1, 3 and 5 were also established.

UR - http://www.scopus.com/inward/record.url?scp=84902118820&partnerID=8YFLogxK

U2 - 10.1039/c4dt00770k

DO - 10.1039/c4dt00770k

M3 - Article

AN - SCOPUS:84902118820

SN - 1477-9226

VL - 43

SP - 9586

EP - 9595

JO - Dalton Transactions

JF - Dalton Transactions

IS - 25

ER -