Starting from pheophorbide a methyl ester (l), a degradation product of chlorophyll a, novel natural antioxidants of chlorophyll a related chlorins 3, 5(S), S(R), 8(R), 9-13 have been synthesized in high yields. Key steps involve formation of 5(R) and 5(S) via a DBU-promoted asymmetric hydroxylation of 3, and regioselective periodate oxidations of 5 to 8(R) and 9. Since photosynthetic organisms...

A new family of Tetraazamacrocyclic Ru(II) complexes [RuCl2(L)] (where L = N4 donor macrocyclic ligands) have been synthesized by the reactions of [RuCl2(DMSO)4] with some of macrocyclic Schiff base ligands containing N4 donor groups. The complexes were characterized by elemental analysis, IR, H, C NMR, mass, electronic, molar conductance and magnetic susceptibility measurements. An octahedral ...

In Cs(2)SbCl(6) and related compounds antimony appears as Sb(III) and Sb(V) in alternate halide octahedra. The optical spectrum contains "mixed valence" peaks assigned to Sb(III) --> Sb(V) transfer near 18 and 27 kK (cm(-1)). In addition there is a peak near 31 kK assigned to an internal transition on Sb(III) and one near 37 kK assigned to Sb(V), mixed with the absorption edge of the crystal. T...

Complexes between oxovanadium (IV) cation and flavonoid derivatives were developed recently in order to increase the intestinal absorption and to reduce the toxicity of vanadium compounds. For these reasons, is interesting to investigate the complexation process between flavonoid rutin (Rut) and vanadyl cation in order to isolate new complexes. Two new complexes [VO(Rut)(H2O)2](SO4)0.5 x 2 H2O ...

* Corresponding Author: Tel.: +91 9436508446; fax: +91 3812374802. E-mail address: [email protected]; [email protected] Abstract Interaction of pinacyanol chloride (PIN) with anionic surfactants at premicellar and postmicellar concentration range was studied by visible spectrophotometry and these interaction produces a blue shift metachromatic band (at ~ 490 nm), which gradually shifted t...