Journal ArticleDOI
The silica-like extended polymorphism of cobalt(II) imidazolate three-dimensional frameworks: X-ray single-crystal structures and magnetic properties.
Yun-Qi Tian,Yun-Qi Tian,Chen-Xin Cai,Xiao-Ming Ren,Chun-Ying Duan,Yan Xu,Song Gao,Xiao-Zeng You +7 more
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TLDR
The new synthetic strategy affords four polymorphous frameworks of cobalt(II) imidazolates of crystalline substances, of which the compound 4 is an isomorphous compound of [Zn(im)(2)]( infinity ), which was also synthesized in a gas-phase reaction in 1980.Abstract:
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) A, 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) A, orthorhombic, Fdd2, Z = 16; 2: a = 17.635(4), b = 27.706(6), c = 9.0810(18) A, 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) A, beta = 91.977(1) degrees, monoclinic, P2(1)/n, Z = 4. All polymorphous frameworks of cobalt(II) imidazolates reflect the structural features of silica (SiO(2)) 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.read more
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Journal ArticleDOI
Exceptional chemical and thermal stability of zeolitic imidazolate frameworks
Kyo Sung Park,Zheng Ni,Adrien P. Côté,Jae Yong Choi,Rudan Huang,Fernando J. Uribe-Romo,Hee K. Chae,Michael O'Keeffe,Omar M. Yaghi +8 more
TL;DR: Study of the gas adsorption and thermal and chemical stability of two prototypical members, ZIF-8 and -11, demonstrated their permanent porosity, high thermal stability, and remarkable chemical resistance to boiling alkaline water and organic solvents.
Journal ArticleDOI
Hydrogen Storage in Metal–Organic Frameworks
Journal ArticleDOI
Synthesis, Structure, and Carbon Dioxide Capture Properties of Zeolitic Imidazolate Frameworks
Anh Phan,Christian J. Doonan,Fernando J. Uribe-Romo,Carolyn B. Knobler,Michael O'Keeffe,Omar M. Yaghi +5 more
TL;DR: The general preparation of crystalline ZIFs is described, discussing the methods that have been developed to create and analyze the variety of materials afforded and how complexity might be introduced into new structures.
Journal ArticleDOI
Ligand‐Directed Strategy for Zeolite‐Type Metal–Organic Frameworks: Zinc(II) Imidazolates with Unusual Zeolitic Topologies
Journal ArticleDOI
Metal Azolate Frameworks: From Crystal Engineering to Functional Materials
TL;DR: A comparison study of 3D Networks Based on Polypyrazolates, Metal 1,2,4-Triazolate Frameworks, and Univalent Coinage-Metal Tetrazolate Framework 1025.
References
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Introduction to solid state physics
TL;DR: In this paper, the Hartree-Fock Approximation of many-body techniques and the Electron Gas Polarons and Electron-phonon Interaction are discussed.