The silica-like extended polymorphism of cobalt(II) imidazolate   three-dimensional frameworks: X-ray single-crystal structures and   magnetic properties

doi:10.1002/chem.200304957

CORC > 北京大学 > 化学与分子工程学院

	The silica-like extended polymorphism of cobalt(II) imidazolate three-dimensional frameworks: X-ray single-crystal structures and magnetic properties
	Tian, YQ ; Cai, CX ; Ren, XM ; Duan, CY ; Xu, Y ; Gao, S ; You, XZ
刊名	chemistry a european journal
	2003
关键词	cobalt coordination polymers magnetic properties N ligands zeolite analogues COMPLEXES NI CO FERROMAGNET CHEMISTRY CU,ZN-SOD POLYMERS PYRAZINE COMPOUND DESIGN
DOI	10.1002/chem.200304957
英文摘要	Five polymorphous frameworks of cobalt(II) imidazolates (1-5) have been prepared by solvatothermal syntheses. Of these, compound 3 has already been synthesized in a gas-phase reaction by Seel et al. in 1969 and structurally characterized by Sturm et al. in 1975. The new synthetic strategy affords four polymorphous frameworks of cobalt(II) imidazolates (1, 2, 4, 5) of crystalline substances, of which the compound 4 (a = b = 23.450(3), c = 12.460(3) Angstrom, tetragonal, I4(1)cd, Z = 16) is an isomorphous compound of [Zn(im)(2)](infinity), which was also synthesized in a gas-phase reaction in 1980. The frameworks of compounds 1 and 2 are porous and isostructural; they have the same framework topology that represents a novel uninodal (6,4)-net: 1: a = 18.513(4), b = 24.368(5), c = 9.2940(19) Angstrom, orthorhombic, Fdd2, Z = 16; 2: a = 17.635(4), b = 27.706(6), c = 9.0810(18) Angstrom, orthorhombic, Fdd2, Z = 16. The framework of compound 5 exhibits a topology of zeolitic structure with the unit-cell parameters: a = 24.3406(8), b = 9.4526(3), c = 24.8470(8) Angstrom, beta = 91.977(1)degrees, monoclinic, P2(1)/n, Z = 4. All polymorphous frameworks of cobalt(II) imidazolates reflect the structural features of silica (SiO2) and also exhibit different magnetic behaviors, although the imidazolates transmit the antiferromagnetic coupling between the cobalt(II) ions in all cases. However, the uncompensated antiferromagnetic couplings arise from spin-canting are sensitive to the structures: compound 1 is an antiferromagnet with T-N = 13.11 K; compounds 2-4 are weak ferromagnets (canted antiferromagnets): 2 shows a very weak ferromagnetism below 15 K, 3 exhibits a relatively strong ferromagnetism below 11.5 K and a coercive field (H-C) of 1800 Oe at 1.8 K, and 4 displays the strongest ferromagnetism of the three cobalt imidazolates and demonstrates a T-C of 15.5 K with a coercive field, H-C, of 7300 Oe at 1.8 K. However, compound 5 seems to be a hidden canted antiferromagnet with a magnetic ordering temperature of 10.6 K.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000186886800026&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; Chemistry, Multidisciplinary; SCI(E); EI; 184; ARTICLE; 22; 5673-5685; 9
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/255813]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Tian, YQ,Cai, CX,Ren, XM,et al. The silica-like extended polymorphism of cobalt(II) imidazolate three-dimensional frameworks: X-ray single-crystal structures and magnetic properties[J]. chemistry a european journal,2003.
APA	Tian, YQ.,Cai, CX.,Ren, XM.,Duan, CY.,Xu, Y.,...&You, XZ.(2003).The silica-like extended polymorphism of cobalt(II) imidazolate three-dimensional frameworks: X-ray single-crystal structures and magnetic properties.chemistry a european journal.
MLA	Tian, YQ,et al."The silica-like extended polymorphism of cobalt(II) imidazolate three-dimensional frameworks: X-ray single-crystal structures and magnetic properties".chemistry a european journal (2003).