The title salt, C24H24N(+)·BF4 (-), is one of two possible dias-tereoisomers having a different configuration of the asymmetric centre in the α-phenyl-ethyl substituent, whose absolute configuration was established to be R. The two phenyl substituents of the cation have a cofacial orientation, albeit with a long centroid-centroid separation of 4.129 (3) Å. The crystal structure exhibits numerou...

In the title salt, C(13)H(19)N(2) (+)·BF(4) (-), an ionic liquid, the butyl and ethyl substituents bonded to the N atoms of the imidazole ring [r.m.s. deviation = 0.019 (1) Å] adopt equatorial positions. The crystal structure exhibits slipped π-π inter-actions between the imidazole and benzene rings of neighbouring mol-ecules [centroid-centroid distance = 3.529 (2) Å]. In the tetra-fluoro-borat...

We propose what is, to our knowledge, a novel method of generating tunable narrow-bandwidth picosecond pulses in which the chirp of equally stretched pump and signal is canceled by difference-frequency mixing. The effect of the group-velocity mismatch on the output pulse bandwidth is analyzed. The method is proved experimentally by generation of pulses of 3.3-cm21 bandwidth and 10-ps duration i...

Hurwitz, Charles (Veterans Administration Hospital, Albany, N.Y.), and Carmen L. Rosano. Evidence for a streptomycin permease. J. Bacteriol. 90:1233-1237. 1965.-The hypothesis that an induced streptomycin permease is required for entry of the antibiotic into cells is further supported by the finding that proflavine and borate, which inhibit transcription, also block the lethal action of strepto...

Isolated guanidinium ions and tetra-phenyl-borate ions are present in the crystal structure of the title compound, C(11)H(22)N(3)O(2) (+)·C(24)H(20)B(-). In the guanidinium ion, the dihedral angle between the N/C/N and C/C/C planes being 49.9 (1)°. The six-membered ring exhibits a half-chair conformation. The C-N bond lengths in the cation range between 1.3335 (16) and 1.3552 (16) Å, indicating...

An in situ approach involving a simple mix and shake method for testing the enantiopurity of primary, secondary and tertiary chiral amines and their derivatives, chiral amino alcohols, by (1)H-NMR spectroscopy is developed. The protocol involves the in situ formation of chiral ammonium borate salt from a mixture of C2 symmetric chiral BINOL, trialkoxyborane and chiral amines. The proposed conce...

We theoretically and experimentally investigate the conditions necessary to realize highly indistinguishable single-photon sources using parametric down conversion. The visibilities of Hong-Ou-Mandel (HOM) interference between photons in different fluorescence pairs were measured and a visibility of 95.8 ± 2% was observed using a 0.7-mm-long beta barium borate crystal and 2-nm bandpass filters,...

We report the atomic-scale structure of a Zn₁₅₂Al-borate layered double hydroxide (LDH) nanosheet, as determined by reverse Monte Carlo (RMC) modelling of X-ray total scattering data. This study involves the extension of the RMC method to enable structural refinement of two-dimensional nanomaterials. The refined LDH models show the intra-layer geometry in this highly-exfoliated phase to be cons...

For the first time, we give a fundamental understanding of the effect of borate-modified nanodiamond on propane oxidative dehydrogenation reaction. Upon increasing the loading amount of borate on the carbon surface, the propene selectivity shows a volcanic curve. The adsorption sites of borate at different loading amounts are thoroughly considered.