Phenothiazine ligands

Photolysis reactions often are associated with oxidation because the latter category of reactions frequently can be initiated by light. The photooxidation of phenothiazines with the formation of N- and S-oxides is typical. But photolysis reactions are not restricted to oxidation. In the case of sodium nitroprusside, it is believed that degradation results from loss of the nitro-ligand from the molecule, followed by electronic rearrangement and hydration. Photo-induced reactions are common in steroids [36] an example is the formation of 2-benzoylcholestan-3-one following irradiation of cholest-2-en-3-ol benzoate. Photoadditions of water and of alcohols to the electronically excited state of steroids have also been observed [37],... 

Optical measurements have been reported for [Ru(bipy)3], [Ru(bipy)2(biq)f, and [Ru(biq)3] (biq = 2,2 -biquinolyl) together with the temperature dependence (84—330 K) of the luminescence emission. The behaviour of the three complexes is rationalized in terms of states derived from a simple orbital model. A description of the photophysical and redox properties of the luminescent complexes [RuLL L ] (where L = 2,2 -bipyridyl, L = 2,2, 2"-terpyridyl, and L" = phenothiazine, N-methylphenothiazine, thian-threne, or H2O) has appeared, and this suggests that states other than the luminescent state are populated. Coupling between dissimilar ligands in the excited states of [Ru(bipy) (phen)3 f, [Ru(bipy) L3 and... 

Phenothiazine cholinesterase inhibitors. Synthetic derivatives of phe-nothiazine are well-tolerated drugs against a variety of human ailments from psychosis to cancer. A number of synthetic N-10-carbonyl phenothiazine derivatives, with cholinesterase inhibitory activity, were tested for interaction with a variety of neurotransmitter receptor systems. Phenothiazines can be prepared without significant neurotransmitter receptor interactions while retaining high potency as cholinesterase ligands for treatment of AD [165],... 

The ease of interaction of Ni(0) complexes with organic substrates has been shown to depend upon both the ligands on nickel and the solvent. The presence of a,a-bipyridyl with the Ni(0) complex and the alkyne led to the isolation of a nickelacyclopropene, an observation in accord with the recently proposed metallocyclic pathway for the Ni(0)-cata-lyzed trimerization of alkynes. Allylic and benzylic ethers and epoxides have been observed to undergo oxidative insertion of Ni(0) into their C-0 bonds with solvent (TMEDA > THE > Et O > CeHe) and ligand (EtsP > PhsP a,a-bipy > COD) effects consistent with an electron-transfer attack by Ni(0). With such sulfur heterocycles as dibenzothiophene, phenoxathiin, phenothiazine, and thian-threne, a 1 1 admixture of (COD)2Ni with a,a-bipyridyl gave as the principal product the desulfurized, ring-contracted cyclic product. 

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