Tuning the host-guest interactions in a phosphine coordination polymer through different types of post-synthetic modification

Ana J Nuñez; Maxwell S Chang; Ilich A Ibarra; Simon M Humphrey

doi:10.1021/ic4022239

Tuning the host-guest interactions in a phosphine coordination polymer through different types of post-synthetic modification

Inorg Chem. 2014 Jan 6;53(1):282-8. doi: 10.1021/ic4022239. Epub 2013 Dec 20.

Authors

Ana J Nuñez¹, Maxwell S Chang, Ilich A Ibarra, Simon M Humphrey

Affiliation

¹ Department of Chemistry, The University of Texas at Austin , 105 E 24th Street A5300, Welch Hall 2.204, Austin, Texas 78712-1224, United States.

PMID: 24359324
DOI: 10.1021/ic4022239

Abstract

The porous Phosphine Coordination Material, PCM-10 contains abundant free P(III) donor sites that can be subjected to a variety of post-synthetic modifications. The diverse P(III)/P(V) organic reactivity and coordination chemistry available to aryl phosphines have been exploited to decorate the pores of PCM-10, allowing for an extensive structure-function study. Polar P═O moieties, charged P(+)-CH3 phosphonium species with exchangeable coanions (I(-), F(-), BF4(-), and PF6(-)) and P-AuCl groups have been successfully post-synthetically incorporated. These modifications directly affect the strength of the resulting host-guest interactions, as demonstrated by comparative sorption studies of CO2, H2, and other gases in the solid-state. Broad tunability of the enthalpy of CO2 adsorption is observed: incorporation of BF4(-) ions inside the pores of PCM-10 results in 24% enhancement of the isosteric adsorption enthalpy of CO2 compared to the parent material, while F(-) anions induce a 36% reduction. Meanwhile, AuCl-decorated PCM-10 shows a high H2 sorption capacity of 4.72 wt % at 77 K and 1.0 bar, versus only 0.63 wt % in the unmodified material.