Electrical conductance, ultrasonic relaxation, and microwave dielectric relaxation of sodium perchlorate in tetrahydrofuran

Abstract

The coefficients C, and D are not independent; an expansion of this form was used only for purposes of convenience and was subsequently converted to a more simplified form. (17) Functions of this form to represent the calculated values of coupling constants (EHT method) were proposed previously: K.

The critical role of configurational flexibility in facilitating reversible reactive metal deposition from borohydride solutions

“…This relationship between ionicity and concentration, though unlike that of traditional aqueous electrolytes, has previously been observed for electrolytes consisting of low permittivity solvents,. [39][40][41][42][43] The strong association tendencies of BH 4with metal cations in THF, as found in previous studies, [18][19][20] suggests Please do not adjust margins Please do not adjust margins that Ca(BH4)2 would be likewise strongly associating in THF even at low concentrations. Indeed, the very low ionic conductivity measured at 0.1 M (0.0038 mS/cm) implies the dominance of undissociated neutral species at this concentration since this conductivity value is nearly two orders of magnitude lower than the value we measure (0.17 mS/cm) for a more weaklyassociating tetrabutylammonium (NBu4 + ) borohydride solution at the same concentration in THF.…”

“…long-range electrostatics), may affect the various cluster equilibria differently, which we plan to investigate in upcoming work. To test whether the presence of dipolar clusters could facilitate formation of ionic species at high concentration through permittivity increases, as previously observed in other strongly associating electrolytes, 32,[40][41][44][45][46] we conducted simulations to determine the influence of several proposed clusters on the solution dielectric constant (supplementary information, Figure S6). The computed lowest free energy electrolyte structure, THF3Ca(BH4)2, possesses a bent geometry and a calculated dipole moment of 5 Debye.…”

Nitrogen-15 and oxygen-17 nuclear magnetic resonance of organophosphorus compounds. Experimental and theoretical determinations of nitrogen-15-phosphorus-31 and oxygen-17-phosphorus-31 nuclear spin coupling constants

“…Additionally, in 12 the P=O coupling is assigned the value of 145 H z because of the similarity to that observed in 10 and 11. It is readily apparent that the couplings to the phosphoryl oxygen in 10- 16 a These values correspond to an average between trigonal and pyramidal geometries at the nitrogen. example, P-C,42 P-H,43 P-Se,44 and P-W,45 follow this trend.…”

Characterization of Tetrahydrofuran as a Solvent for Proton Transfer Reactions

“…It follows that the thermodynamic equilibrium constants for the ionization and overall dissociation of HA (defined under Table I where CHA is the total (analytical) concentration of HA, the ionization constant gi HA is defined under [A-] = (K,HACHA + KdCACcA)Ln/fl [6] from which it follows that asm = ~ , [7] Ka~CHA "[ 1/2 It follows that the thermodynamic equilibrium constants for the ionization and overall dissociation of HA (defined under Table I where CHA is the total (analytical) concentration of HA, the ionization constant gi HA is defined under [A-] = (K,HACHA + KdCACcA)Ln/fl [6] from which it follows that asm = ~ , [7] Ka~CHA "[ 1/2…”

“…The formation of contact and solvent separated ion pairs could be distinguished (2). In some cases the conductivity data could be supplemented by ultrasonic relaxation measurements, providing information on the dynamics of the association processes (6,7,11).…”