An "S"-shaped pentanuclear CuII cluster derived from the metal-assisted hydrolysis of pyCOpyCOpy: structural, magnetic and spectroscopic studies.
Reaction of [Cu2(O2CMe)4(H2O)2] with 2,6-di-(2-pyridylcarbonyl)-pyridine (pyCOpyCOpy or dpcp) in MeCN-H2O 10:1, led to the pentanuclear copper(II) complex [Cu5(O2CMe)6{pyC(O)(OH)pyC(O)(OH)py}2] () which crystallizes in the triclinic P1 space group. The copper(II) atoms are arranged in an "S"-shaped configuration, and are bridged by the doubly deprotonated bis(gem-diol) form of the ligand, pyC(O)(OH)pyC(O)(OH)py2-. Magnetic susceptibility data indicate the interplay of both ferro- and antiferromagnetic intramolecular interactions stabilizing an S=3/2 ground state. Fitting of the data according to a next-nearest-neighbour model {H=-[J1(S1S2+S1'S2')+J2(S2S3+S3'S2')+J3(S1S3+S3'S1')+J4(S2S2')]} yields exchange coupling constants J1=+39.7 cm(-1), J2=-15.9 cm(-1), J3=-8.3 cm(-1) and J4=+4.3 cm(-1), leading to an S=3/2 ground state. X-Band EPR spectroscopy indicates a zero-field splitting of the ground state with |D3/2|=0.38 cm(-1).
Institute of Materials Science, NCSR Demokritos, 153 10 Aghia, Paraskevi, Attikis, Greece. tbou@ims.demokritos.gr
Athanassios K
AK
Boudalis
Catherine P
CP
Raptopoulou
Vassilis
V
Psycharis
Yiannis
Y
Sanakis
Belén
B
Abarca
Rafael
R
Ballesteros
Mimoun
M
Chadlaoui
D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D006868:Hydrolysis; D008280:Magnetics; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D013057:Spectrum Analysis
D009942:Organometallic Compounds; D011725:Pyridines; D003300:Copper