TY - JOUR
T1 - Azido-bridged Cu(II) compounds with asymmetric end-to-end and end-on binding modes
T2 - Magnetic assignments using a spin dimer model
AU - You, Young Sin
AU - Hong, Chang Seop
AU - Kim, Kwan Mook
N1 - Funding Information:
This work is financially supported by the CRM-KOSEF. C.S.H. would like to thank an Operation Program on Shared Research Equipment of KBSI and MOST.
PY - 2005/1/27
Y1 - 2005/1/27
N2 - Dinuclear [Cu(aepi)(N3)2]2 (1) [aepi = 1-(2-aminoethyl)piperidine] and 1D chain [Cu(aepy)(N3) 2]n (2) [aepy = 1-(2-aminoethyl)pyrrolidine] have been prepared and characterized by means of X-ray analysis and magnetic measurements. For 1, the Cu(II) centers are doubly bridged by end-on (EO) azido units in a basal-apical fashion. The molecular structure of 2 features magnetic centers that are linked by μ-1,1,3 azido groups, forming a 1D chain with alternating EO and end-to-end (EE) azido bridging patterns. The magnetic data for the dinuclear complex 1 were fitted with the Bleaney-Bowers equation derived from the Hamiltonian H = -JS1 • S2, affording parameters of g = 2.093(1), J = -3.06(1) cm-1 and zJ′ = -1.32(3) cm -1. This indicates that the EO azido group mediates an antiferromagnetic interaction. Complex 2 has two possible magnetic pathways: one is through the EO azido bridge (Jeo) and the other via the EE bridge (Jee). The alternating chain model with ferromagnetic and antiferromagnetic interactions based on the exchange Hamiltonian H = -∑iS2i • S2i + 1 + J2S 2i • S2i - 1] was employed, leading to g = 2.076(2), J1 = -3.22(5) cm-1, J2 = 17.0(5) cm -1 and zJ′ = -1.34(6) cm-1. By taking into account structural parameters of 1 and 2, it is rationally suggested that J1 and J2 are ascribed to Jeo andJee, respectively. These assignments are also ascertained by MO calculations using a spin dimer model.
AB - Dinuclear [Cu(aepi)(N3)2]2 (1) [aepi = 1-(2-aminoethyl)piperidine] and 1D chain [Cu(aepy)(N3) 2]n (2) [aepy = 1-(2-aminoethyl)pyrrolidine] have been prepared and characterized by means of X-ray analysis and magnetic measurements. For 1, the Cu(II) centers are doubly bridged by end-on (EO) azido units in a basal-apical fashion. The molecular structure of 2 features magnetic centers that are linked by μ-1,1,3 azido groups, forming a 1D chain with alternating EO and end-to-end (EE) azido bridging patterns. The magnetic data for the dinuclear complex 1 were fitted with the Bleaney-Bowers equation derived from the Hamiltonian H = -JS1 • S2, affording parameters of g = 2.093(1), J = -3.06(1) cm-1 and zJ′ = -1.32(3) cm -1. This indicates that the EO azido group mediates an antiferromagnetic interaction. Complex 2 has two possible magnetic pathways: one is through the EO azido bridge (Jeo) and the other via the EE bridge (Jee). The alternating chain model with ferromagnetic and antiferromagnetic interactions based on the exchange Hamiltonian H = -∑iS2i • S2i + 1 + J2S 2i • S2i - 1] was employed, leading to g = 2.076(2), J1 = -3.22(5) cm-1, J2 = 17.0(5) cm -1 and zJ′ = -1.34(6) cm-1. By taking into account structural parameters of 1 and 2, it is rationally suggested that J1 and J2 are ascribed to Jeo andJee, respectively. These assignments are also ascertained by MO calculations using a spin dimer model.
KW - Azide ligand
KW - Copper(II) compounds
KW - Crystal structures
KW - Magnetic properties
UR - http://www.scopus.com/inward/record.url?scp=12344290604&partnerID=8YFLogxK
U2 - 10.1016/j.poly.2004.11.022
DO - 10.1016/j.poly.2004.11.022
M3 - Article
AN - SCOPUS:12344290604
SN - 0277-5387
VL - 24
SP - 249
EP - 256
JO - Polyhedron
JF - Polyhedron
IS - 2
ER -