Irreversible transformation of chiral to achiral polymorph of   K[Co(HCOO)(3)]: synthesis, structures, and magnetic properties

doi:10.1039/c0dt01701a

CORC > 北京大学 > 化学与分子工程学院

	Irreversible transformation of chiral to achiral polymorph of K[Co(HCOO)(3)]: synthesis, structures, and magnetic properties
	Duan, Zhiming ; Wang, Zheming ; Gao, Song
刊名	dalton transactions
	2011
关键词	METAL-ORGANIC FRAMEWORKS DIAMOND FRAMEWORK CRYSTAL-STRUCTURE WEAK FERROMAGNETISM PHASE-TRANSITION SUPRAMOLECULAR ISOMERISM COBALT(II) COMPLEXES POTASSIUM FORMATE GUEST INCLUSION CO
DOI	10.1039/c0dt01701a
英文摘要	We report the rare observation of an irreversible transformation from a chiral to an achiral crystal through the syntheses of two polymorphs of K[Co(HCOO)(3)], and their characterization using single and powder crystal X-ray diffractions, infrared spectroscopy, thermal analyses, and the study of their magnetic properties. The kinetic phase (1), obtained under a high concentration of reactants, has a chiral (4(9).6(6)) framework and adopts the hexagonal space-group P 6(3)22. The thermodynamic phase (2), obtained from dilute solution, has an achiral (4(12).6(3)) framework and adopts a monoclinic space group C 2/c. Once 1 has crystallized out from the concentrated solution, it dissolves slowly at the expense of the formation of 2. In the solid state 1 is irreversibly transformed to 2 very slowly at ambient conditions. The transformation is accompanied by an increase of the crystal density, a change of coordination mode of some formates from anti-anti to syn-anti and a change in the coordination number of K from 6 to 8. 1 is a spin-canted antiferromagnet (T-N = 8.3 K) displaying two steps in the isothermal magnetization at 2 K, a spin-flop at 1.2 kOe and a flip to paramagnetic phase at 42.0 kOe. 2 is an antiferromagnet (T-N = 2.0 K). Thermal properties and IR spectra of the two polymorphs have been studied, showing some differences.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000289686600016&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; Chemistry, Inorganic & Nuclear; SCI(E); EI; PubMed; 18; ARTICLE; 17; 4465-4473; 40
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/150019]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Duan, Zhiming,Wang, Zheming,Gao, Song. Irreversible transformation of chiral to achiral polymorph of K[Co(HCOO)(3)]: synthesis, structures, and magnetic properties[J]. dalton transactions,2011.
APA	Duan, Zhiming,Wang, Zheming,&Gao, Song.(2011).Irreversible transformation of chiral to achiral polymorph of K[Co(HCOO)(3)]: synthesis, structures, and magnetic properties.dalton transactions.
MLA	Duan, Zhiming,et al."Irreversible transformation of chiral to achiral polymorph of K[Co(HCOO)(3)]: synthesis, structures, and magnetic properties".dalton transactions (2011).