Self-assembly of high-nuclearity copper cages: tricorne Cu21 and saddlelike cyclic Cu16.
Reaction of cupric salts with H(2)Rppz (R = H, Me; H(2)ppz = 3-(2-hydroxyphenyl)pyrazole; H(2)Meppz = 3-(2-hydroxy-5-methylphenyl)pyrazole) in the presence of sodium azide and triethylamine as bases gave two high-nuclearity copper cage compounds [HNEt(3)](2)[Cu(21)(CH(3)CN)(2)(H(2)O)(mu(2)-N(3))(6)(mu(3)-N(3))(2)(ppz)(18)](H(2)O)(3)(EtOH)(2) (1) and [Cu(16)(EtOH)(2)(H(2)O)(2)(Meppz)(16)]9.5 H(2)O (2), respectively. X-ray crystallographic studies revealed that molecular skeletons of 1 and 2 are unique tricorne Cu(21) and saddlelike cyclic Cu(16) aggregates, respectively. The magnetic properties studies showed overall antiferromagnetic interactions in 1 and 2. Quantum Monte Carlo simulations by using a 3-J model for 1 and a 2-J model for 2 were performed, which indicated that the magnetic couplings within the triangular copper units in 1 are ferromagnetic and those between other copper ions are antiferromagnetic, whereas in 2 all magnetic couplings between adjacent copper ions are exclusively antiferromagnetic.
Bai
Yue-Ling
YL
State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China.
Tangoulis
Vassilis
V
Huang
Rong-Bin
RB
Zheng
Lan-Sun
LS
Tao
Jun
J