The addition of alkali or silver salts of dicyanoamide (dca), tricyanomethanide (tcm) and tetracyanoborate (tcb) to a solution of B(C(6)F(5))(3) in diethyl ether affords salts containing very voluminous B(C(6)F(5))(3) adduct anions of the type [E(CN)(n)(-)] x [B(C(6)F(5))(3)](n): E = N (dca_nb with n = 1, 2; b = B(C(6)F(5))(3)); E = C (tcm_nb with n = 1, 2, 3), and E = B (tcb_nb with n = 1, 2, 3, 4). Salts bearing these anions such as B[(CN) x B(C(6)F(5))(3)](4)(-) (= [B(CN)(4)(-)] x [B(C(6)F(5))(3)](4)), C[(CN) x B(C(6)F(5))(3)](3)(-) (= [C(CN)(3)(-)] x [B(C(6)F(5))(3)](3)), and N[(CN) x B(C(6)F(5))(3)](2)(-) (=[N(CN)(2)(-)] x [B(C(6)F(5))(3)](2)) can be prepared in good yields. They are thermally stable up to over 200 degrees C and dissolve in polar organic solvents. Depending on the stoichiometry mono-, di-, tri-, or tetraadduct formation is observed. The solid state structures of dca_2b, tcm_3b and tcb_4b salts show only long cation...anion contacts and thereby weak interactions, large anion volumes and only small distortions of the dca, tcm or tcb core enwrapped between B(C(6)F(5))(3) groups. That is why these anions can be regarded as weakly coordinating anions. On the basis of B3LYP/6-31+G(d) computations the energetics, structural trends and charge transfer of the adduct anion formation were studied. Since tcm_3b and tcb_4b are easily accessible and can also be prepared in large quantities, these anions may be utilized as a true alternative to other widely used weakly coordinating anions. Moreover, for both steric and electronic reasons it seems reasonable to expect that as counterions for cationic early transition metal catalysts such anions may show reduced ion pairing and hence increased catalytic activity.

This study examines the use of tetrahedral [E(O–C6X4–CN)4]– anions (E = B, Al; X = H, F), which can be synthesized from the reaction of tetrahedral NaBH4/LiAlH4 and HO–C6X4–CN, as anionic linkers for the generation of 2D and 3D crystalline coordination polymer networks. Such polymer networks were obtained by the connection of tetrahedral p‐cyanophenoxy aluminate or borate linkers with monocationic metal centers such as Li+, Na+, Ag+, and Cu+. These studies are specifically focused on the synthesis, structure, and stability of such polymers. Additionally, the perfluorinated O–C6F4–CN linker was used to study electronic influences. Salts bearing the perfluorinated [E(O–C6F4–CN)4]– anion decompose into E(O–C6F4–CN)3 and [O–C6F4–CN]–, which is also observed when a Lewis acid such as B(C6F5)3 is added. Moreover, addition of B(C6F5)3 leads to the formation of molecular‐ion pairs because the cyano groups are now either completely or partly blocked. The structures of M[Al(O–C6H4–CN)4] (M = Li, Ag, Cu), Na[B(O–C6H4–CN)4], and Li[Al(O–C6F4–CN)4] as well as of the decomposition products Na(O–C6F4–CN), (THF)Al[O–C6H4–CN·B(C6F5)3]3 (THF = tetrahydrofuran), Na[(F5C6)3B·O–C6H4–CN·B(C6F5)3], and Li[NC–C6F4–O–Al{O–C6F4–CN·B(C6F5)3}3] are discussed.

In this work data of the molar enthalpies of formation of the ionic liquid 1-methylimidazolium nitrate [H-MIM][NO3] was measured by means of combustion calorimetry. The molar enthalpy of fusion of [H-MIM][NO3] was measured using DSC. Experiments to vaporize the ionic liquid into vacuum or nitrogen stream in order to obtain vaporization enthalpy have been performed. Ab initio calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the G3MP2 theory. The combination of traditional combustion calorimertry with modern high-level ab initio calculations allow the determination of the molar enthalpy of vaporization of the ionic liquid under study. The ab initio calculations indicate that [H-MIM][NO3] is most probably separated into the neutral species methyl-imidazole and HNO3 in the gaseous phase at conditions of the vaporization experiments.

Thermochemical studies of the ionic liquids 1-ethyl-3-methylimidazolium tricyanomethanide [C(2)MIM][C(CN)(3)] and 1-butyl-3-methylimidazolium tricyanomethanide [C(4)MIM][C(CN)(3)] have been performed in this work. Vaporization enthalpies have been obtained using a recently developed quartz crystal microbalance (QCM) technique. The molar enthalpies of formation of these ionic liquids in the liquid state were measured by means of combustion calorimetry. A combination of the results obtained from QCM and combustion calorimetry lead to values of gaseous molar enthalpies of formation of [C(n)MIM][C(CN)(3)]. First-principles calculations of the enthalpies of formation in the gaseous phase for the ionic liquids [C(n)MIM][C(CN)(3)] have been performed using the CBS-QB3 and G3MP2 theory and have been compared with the experimental data. Furthermore, experimental results of enthalpies of formation of imidazolium-based ionic liquids with the cation [C(n)MIM] (where n = 2 and 4) and anions [N(CN)(2)], [NO(3)], and [C(CN)(3)] available in the literature have been collected and checked for consistency using a group additivity procedure. It has been found that the enthalpies of formation of these ionic liquids roughly obey group additivity rules.

An apparatus combining a vibrating-wire viscometer and a single-sinker densimeter was used to provide accurate ηρpT data for four isotherms on ethane at (293.15, 307.15 [ethane 3.5 and 5.0], and 423.15) K and five isotherms on propane at (273.15, 298.15, 366.15, 373.15, and 423.15) K. The maximum pressure was chosen to be about 95 % of the saturated vapor pressure for the subcritical isotherms and 30 MPa at maximum for the supercritical isotherms. The relative uncertainty in the density is estimated to be less than ± 0.1 %, except for the low-density range. Near the critical region, allocation errors for temperature and pressure have a significant impact on the uncertainty of the experimental densities. The density data agree within ± 0.1 %, when comparing them with values calculated from the equations of state by Bücker and Wagner (2006) for ethane and by Lemmon et al. (2009) for propane, excluding the low-density and the near-critical regions. The near-critical isotherms at 307.15 K for ethane and at 373.15 K for propane reveal differences of +2.1 % and +1.2 %, respectively, in accordance with the estimated maximum total uncertainties of the experimental pρT data for these isotherms. The viscosity measurements are characterized by a relative uncertainty of ± (0.25 to 0.3) %, only increased by 0.04 % in the near-critical region due to the allocation errors arising from the temperature and density measurements. The new viscosity data and additionally re-evaluated earlier data of our group are compared with the viscosity surface correlations by Hendl et al. (1994) for ethane and by Scalabrin et al. (2006) for propane as well as with selected experimental data for the low-density region. For ethane, the maximum deviations of the new data exceed the stated uncertainty of ± 2.5 % for the viscosity surface correlation. For propane, the deviations do not exceed ± 0.7 %, except for the near-critical isotherm at 373.15 K. The effect of the critical enhancement became evident for the near-critical isotherms, about 2 % for ethane at 307.15 K and about 1 % for propane at 373.15 K. The new viscosity data should be used to improve the viscosity surface correlations available in the literature.