Preparation, properties, and reactions of metal-containing heterocycles Part CV. Synthesis and structure of polyoxadiphosphaplatinaferrocenophanes

A series of novel heterobimetallic crown ether-like polyoxadiphosphaplatina ferrocenophanes cis-[1,1 ' -Fc(CH2O(CH2CH2O)(n)CH2CH2PPh2)(2)]PtCl2 (n = 1- 3) (4a-c) was synthesized in good yield by cyclization of the bis(phosphine ) ligands 1,1 ' -Fc(CH2O(CH2CH2O)(n)CH2CH2PPh2)(2) (n = 1-3) (3a-c) and (Ph CN)(2)PtCl2 under high dilution conditions in CH2Cl2. The bisphosphines 3a- c are obtained by reaction of the corresponding diols 1,1 ' -Fc(CH2O(CH2CH2 O)(n)CH2CH2OH)(2) (n = 1- 3) (la-c) with: (i) CH3SO2Cl in CH2Cl2 and (ii) L iPPh2 in THF. Although the X-ray crystal structure of 4a shows that the cav ity is large enough for the encapsulation of small metal cations, inclusion experiments of 4a-c with Group I cations, and Mg2+, or NH4+ in solution ap plying NMR titration and cyclovoltammetric methods reveal no evidence for t he formation of host-guest complexes for 4a,b. In the case of 4c only the a ddition of Na+ or K+ leads to an insignificant effect. (C) 2001 Elsevier Sc ience BN. All rights reserved.