The synthesis of a number of 3d transition metal binary pyrazolates in microcrystalline form, thus suitable for a full XRPD characterization, has been pursued. The crystal and molecular structures of the Fe(pz)(3), Co(pz)(2), Co(pz)(3), and Ni(pz)(2) polymers, together with the few congeners reported in the recent literature, show that these species tend to afford highly crystalline materials where strictly collinear chains of metal atoms are present. Depending on the synthetic strategy used, Ni(pz)(2) has been found to crystallize as two different alpha (orthorhombic) and beta (monoclinic) phases, possessing nearly identical intramolecular features. Data for each compound follow. Fe(pz)(3): C9H9FeN6, hexagonal, P6(3)/m, a = 9.1745(3) Angstrom, c = 7.2191(4) Angstrom, Z = 2. Co(pz)(2): C6H6CoN4, orthorhombic, lbam, a = 7,5239(5) Angstrom, b = 14.3461 (9) Angstrom, c = 7.4331(5) Angstrom, Z = 4. Co(pz)(3): C9H9CoN6, hexagonal, P6(3)/m, a = 9.1966(3) Angstrom, c = 7.1051(3) Angstrom, Z = 2. alpha-Ni(pz)(2): C6H6N4Ni, orthorhombic, Cmcm, a = 16.6758(11) Angstrom, b = 6.4872(4) Angstrom, c = 6.9423(6) Angstrom, Z = 4. beta-Ni(pz)(2): C6H6N4Ni, monoclinic, P2(1)/m, a = 9.967(2) Angstrom, b = 6.975(1) Angstrom, c = 6.016(1), Angstrom, beta = 98.50(1)degrees, Z = 2. The thermal stability and the detailed structural properties of these model compounds have been evaluated, in the light of the technologically relevant crystal phases (the well-known metal-diazolates showing reversible spin-crossover or spin-transition behavior) obtainable upon doping, magnetic dilution, and ring substitution (in the 4-position).
One-dimensional polymers containing strictly collinear metal ions: Synthesis and XRPD characterization of homoleptic binary metal pyrazolates / N. Mascocchi, G. A. Ardizzoia, S. Brenna, G. LaMonica, A. Maspero, S. Galli, A. Sironi. - In: INORGANIC CHEMISTRY. - ISSN 0020-1669. - 41:23(2002), pp. 6080-6089.
Titolo: | One-dimensional polymers containing strictly collinear metal ions: Synthesis and XRPD characterization of homoleptic binary metal pyrazolates |
Autori: | SIRONI, ANGELO AGOSTINO DANIELE (Ultimo) |
Parole Chiave: | RAY-POWDER DIFFRACTION CONDUCTING COORDINATION POLYMERS TRANSITION MOLECULAR MATERIALS SPIN-CROSSOVER BEHAVIOR MAGNETIC-PROPERTIES CRYSTAL-STRUCTURE 3,5-DIMETHYLPYRAZOLATE COMPLEXES THERMAL HYSTERESIS CHEMISTRY CHAIN |
Settore Scientifico Disciplinare: | Settore CHIM/03 - Chimica Generale e Inorganica |
Data di pubblicazione: | 2002 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1021/ic025821e |
Appare nelle tipologie: | 01 - Articolo su periodico |