Incongruent Melting La Y Sc(BO): LYSB Nonlinear Optical Crystal Grown by the Czochralski Method.

Nonlinear optical (NLO) crystals with incongruent melting of La Y Sc (BO) ( x + y + z = 4) (LYSB)-type were grown for the first time, to the best of our knowledge, by the Czochralski method. A special thermal assembly was used and the melt composition, growth direction, and the pulling and rotation rates have been optimized. Good optical quality LYSB crystal with a diameter of about 13 mm and a length of 25 mm has been grown from the LaYSc(BO) starting melt composition, along the c-axis direction, using a slow rotation rate of 8-10 rpm and a high pulling rate of 2 mm/h.

Nature of cationic poly(propylenimine) dendrimers in aqueous solutions as studied using versatile indicator dyes.

Aqueous solutions of four cationic poly(propylenimine) low-generation dendrimers of different architecture and hydrophobicity have been examined as media for acid-base reactions of indicator dyes. The cationic dendrimers in solution can be considered as oligomers of cationic polyelectrolytes, or surfactant-like species, able to form micelles through self-association or sometimes even as unimolecular micelles. The dendrimers influence the ionization constants, tautomeric equilibria, and absorption/emission/excitation spectra of indicator dyes.