Noncovalent Synthesis of Hierarchical Zinc Phosphates from a Single Zn4O12P4 Double‐Four‐Ring Building Block: Dimensionality Control through the Choice of …

R Murugavel, S Kuppuswamy, N Gogoi… - … A European Journal, 2010 - Wiley Online Library
Chemistry–A European Journal, 2010Wiley Online Library
In contrast to the well‐known reaction of phosphonic acids RP (O)(OH) 2 with divalent
transition‐metal ions that yields layered metal phosphonates [RPO3M (H2O)] n, the 2, 6‐
diisopropylphenyl ester of phosphoric acid, dippH2, reacts with zinc acetate in methanol
under ambient conditions to afford tetrameric zinc phosphate [(ArO) PO3Zn (MeOH)] 4 (1).
The coordinated methanol in 1 can be readily exchanged by stronger Lewis basic ligands at
room temperature. This strategy opens up a new avenue for building double‐four‐ring …
Abstract
In contrast to the well‐known reaction of phosphonic acids RP(O)(OH)2 with divalent transition‐metal ions that yields layered metal phosphonates [RPO3M(H2O)]n, the 2,6‐diisopropylphenyl ester of phosphoric acid, dippH2, reacts with zinc acetate in methanol under ambient conditions to afford tetrameric zinc phosphate [(ArO)PO3Zn(MeOH)]4 (1). The coordinated methanol in 1 can be readily exchanged by stronger Lewis basic ligands at room temperature. This strategy opens up a new avenue for building double‐four‐ring (D4R) cubane‐based supramolecular assemblies through strong intercubane hydrogen‐bonding interactions. Seventeen pyridinic ligands have been used to synthesize as many D4R cubanes [(ArO)PO3Zn(L)]4 (218) from 1. The ligands have been chosen in such a way that the majority of them contain an additional functional group that could be used for noncovalent synthesis of extended structures. When the ligand does not contain any other hydrogen‐bonding donor–acceptor sites (e.g., 2,4,6‐trimethylpyridine (collidine)), zero‐dimensional D4R cubanes have been obtained. The use of pyridine, lutidine, 2‐aminopyridine, and 2,6‐diaminopyridine, however, results in the formation of linear or zigzag one‐dimensional assemblies of D4R cubanes through strong intermolecular CH⋅⋅⋅O or NH⋅⋅⋅O interactions. Construction of two‐dimensional assemblies of zinc phosphates has been achieved by employing 2‐hydroxypyridine or 2‐methylimidazole as the exo‐cubane ligand on zinc centers. The introduction of an alcohol side chain on the pyridinic ligand in such a way that the CH2OH group cannot participate in intracubane hydrogen bonding (e.g., pyridine‐3‐methanol, pyridine‐4‐methanol, and 3,5‐dimethylpyrazole‐N‐ethanol) leads to the facile noncovalent synthesis of three‐dimensional framework structures. Apart from being useful as building blocks for noncovalent synthesis of zeolite‐like materials, compounds 118 can also be thermolyzed at approximately 500 °C to yield high‐purity zinc pyrophosphate (Zn2P2O7) ceramic material.
Wiley Online Library
以上显示的是最相近的搜索结果。 查看全部搜索结果