Synthesis and Characterization of a New Layered Compound of Trimesic Acidelectronic Supplementary Information (Esi) Available: Top View of the Hxbtc Anionic Network (Fig. S1) and Detailed Hydrogen Bond Graph Sets Present in the Interactions Linking the Two Hxbtc Sheets Within a Double Layer (Fig. S2). See Http://Www.rsc.org/Suppdata/Nj/B1/B108083K/