Formation of racemic crystals of transition metal complexes by grinding 1 : 1 mixtures of enantiomeric crystals.

Thermodynamic study of interaction between some transition metal ions and L-Alanine

Using UV-vis spectrophotometic method, the formation constants for interaction of Cd2+(aq) andCo2+(aq) ions with L-Alanine were experimentally studied at pH = 4.1 ± 0.01 (50mM of potassiumhydrogen phthalate buffer), ionic strength of 0.1M potassium nitrate and at 5 differenttemperatures 15,20, 25,30 and 35°C. The optical absorption spectra of mixtures containingconsidered cations and L-Alanine ...

Formation of racemic compound crystals by mixing of two enantiomeric crystals in the solid state. Liquid transport of molecules from crystal to crystal

STUDY ON THE COMPLEX FORMATION BETWEEN N-PROPYLSALICYLIDENE BASED ON SILICA AS ION EXCHANGER AND SOME TRANSITION METAL IONS

N-propylsalicylidene based on silica as ion exchanger (IE) was used for the separation by complexation of Mn2+, Co2+, Ni2+, Cu2+, Hg2+, Cr3+, Fe3+, and UO22+ from their parent solutions. IE and its metal complexes are characterized by elemental analysis, electronic and infrared spectra, in addition to thermal analysis in atmospheric pressure. The mode of chelation and the proposed geometric str...

Carboxylic acid functionalized ortho-linked oxacalix[2]benzene[2]pyrazine: synthesis, structure, hydrogen bond and metal directed self-assembly.

Cyclooligomerization of 2,6-dichloropyrazine 4 and benzyl 2,3-dihydroxybenzoate 5 under microwave irradiation resulted in a racemic pair of ester functionalized ortho-linked oxacalix[2]benzene[2]pyrazine 6, which was further transformed to the corresponding racemic carboxylic acid functionalized ortho-linked oxacalix[2]benzene[2]pyrazine 3. Both enantiomers of 3 adopt 1,3-alternate conformation...

Effect of impurities on the optical properties of KTP single crystals grown from flux

In the present work, KTP crystals have been grown by spontaneous nucleation technique in flux medium using K6P4O13 flux. 0.4-1 °C/h cooling rates were applied in the spontaneous nucleation process. The presence and amount of impurities has been determined by using XRF. The optical transmission spectra of impure KTP crystals in the UV–visible region are discussed. The transmission cut-off is cle...