Assembly of Lipophilic Tetranuclear (Cu4 and Zn4) Molecular Metallophosphonates from 2,4,6-Triisopropylphenylphosponic Acid and Pyrazole Ligands

• Published in: Inorganic chemistry Vol. 45; no. 8; pp. 3344 - 3351
• Main Authors: Chandrasekhar, Vadapalli, Sasikumar, Palani, Boomishankar, Ramamoorthy, Anantharaman, Ganapathi
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 17.04.2006
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic060003y

A sterically hindered aryl phosphonic acid ArP(O)(OH)2 (2) (Ar = 2,4,6-isopropylphenyl) was synthesized and structurally characterized. ArP(O)(OH)2 forms an interesting hydrogen-bonded corrugated sheet-type supramolecular structure in the solid-state. A three-component reaction involving ArP(O)(OH)2, 3,5-dimethylpyrazole(DMPZH), and Cu(CH3COO)2·H2O produces the tetranuclear Cu(II) compound [Cu4(μ3-OH)2{ArPO2(OH)}2(CH3CO2)2(DMPZH)4][CH3COO]2·CH2Cl2 (3). A similar three-component reaction involving ArP(O)(OH)2, 3,5-dimethylpyrazole, and Zn(CH3COO)2·2H2O yields the tetranuclear Zn(II) compound [Zn4{ArPO3}2{ArPO2(OH)}2{DMPZH}4(DMPZ)2]·5MeOH (4). While 3 has been found to have an asymmetric cage structure where two dinuclear copper cores are bridged by bidentate [ArPO2(OH)]- ligands, 4 possesses an open-book tricyclic structure composed of three fused metallophosphonate rings. Magnetic studies on 3 revealed antiferromagnetic behavior.