Single crystals of five very low-melting ionic liquids, [emim]BF4 (mp -1.3 degrees C), [bmim]PF6 (+1.9 degrees C), [bmim]OTf (+6.7 degrees C), [hexpy]NTf2 (-3.6 degrees C), and [bmpyr]NTf2 (-10.8 degrees C), have been grown using a combined calorimetric and zone-melting approach and their crystal structures determined by X-ray diffraction.

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A series of composites, some with permanent porosity, comprising polymers and ionic liquids have been prepared by in-situ polymerization. The characteristics of both composites and isolated polymers have been investigated. Slow mass and phase transfer characterize the interaction with a range of polymers (1-17) in the N,N′-dialkylimidazolium ionic liquids, [emim]BF 4, [bmim]PF6, or [omim]N(SO2CF3)2. Freeradical homopolymerization of 1-vinyl-2-pyrrolidinone in [bmim]PF6 or of 4-vinylpyridine in [omim]N-(SO2CF3)2 gave viscous solutions from which polymer (Mw ) 162 500 and 71 500 g mol -1 , respectively) could be isolated. Detectable ionic liquid residues were retained in the isolated polymers despite five reprecipitations from methanol. Copolymerization of 4-vinylpyridine (VP) with >5% divinylbenzene (DVB) or trimethylolpropane trimethacrylate (TRIM) in [omim]N(SO2CF3)2, and homopolymerizations of the cross-linking monomers on their own, led with 90-100% monomer conversion to a series of gel-like composite materials, B-H, from which cross-linked polymers, B′-H′, could be isolated by Soxhlet extraction of the ionic liquid. Copolymers of VP with 5-30% DVB (E′, F′) showed a low degree of permanent porosity in the dry state. However, poly(DVB) (G′) and poly(TRIM) (H′) have bulk densities (<0.6 g cm -3 ), intrusion volumes (>0.9 cm 3 g -1 ), BET surface areas (70-320 m 2 g -1 ), and morphology (from SEM studies) which demonstrate the porogenic character of the ionic liquids used. Comparisons with the related products I and J obtained in toluene reveal the sensitivity of these systems both to the properties of the porogen solvent and to the monomer used.

The salts [C6H11N2][AuCl4] (1) and [C8H15N2][AuCl4] (2) ([C6H11N2]+ = 1-ethyl-3-methylimidazolium; [C8H15N2]+ = 1-butyl-3-methylimidazolium), prepared by a solvent-free method, display similar crystal structures. 1 crystallizes in the monoclinic P21/c space group (a = 11.1915(15) Å, b = 12.380(2) Å, c = 9.2883(13) Å; β = 98.810(16)°; Z = 4) and 2 in the triclinic P1̄ space group (a = 7.9354(14) Å, b = 8.3930(15) Å, c = 11.397(2) Å; α = 83.94(2)°, β = 87.93(2)°, γ = 78.04(2)°; Z = 2). In both cases, a unique motif is seen consisting of linear chains of alternating corner-to-face arranged [AuCl4]- ions at Au···Cl separations of 3.356(3) Å (1) and 3.452(3) Å (2). Ionic liquid behavior is observed from 58 to 220 °C for 1 and 50 to 250 °C for 2.