ABSTRACT
We report the details of our success in conferring photocatalytic self-cleaning properties on keratin fibers using modified sol-gel colloids. To the best of our knowledge, we studied for the first time the crucial effect of the concentration of titanium dioxide precursor on colloid composition, properties, and biocompatibility in an attempt to enhance the properties and application of anatase titanium dioxide colloid to keratins. The transparency, the particle size distribution, and the crystallinity of synthesized colloids were systematically investigated. The compatibility of the colloids and keratin substrates is thoroughly compared and discussed. The insights presented contribute to the further understanding of the structure-property-use relationship of titanium dioxide in biomaterial applications.
Subject(s)
Keratins/chemistry , Titanium/chemistry , Biocompatible Materials , Catalysis , Colloids/chemistry , Particle Size , Photochemical ProcessesABSTRACT
A modular design approach has been utilized to develop molecular 'pockets' featuring three integrated components, namely a phosphorescent Pt(II)-pi(organic) moiety, a suitable receptor group, and a rigid, conjugated connecting backbone, and the cavities therein are examined by NMR spectroscopy and an X-ray crystal structure. Their photophysical properties have been investigated; unusually for Pt-terpyridine derivatives, the complexes are luminescent (near-red (3)MLCT emission) in solution at room temperature. It has been shown that their emissive characteristics are affected by the nature of the backbone component but not the receptor group.
Subject(s)
Luminescent Agents/chemistry , Luminescent Agents/chemical synthesis , Organoplatinum Compounds/chemistry , Organoplatinum Compounds/chemical synthesis , Pyridines/chemistry , Chemistry Techniques, Analytical , Crystallography, X-Ray , Luminescent Measurements , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Conformation , Molecular Structure , Spectrophotometry , Spectrophotometry, UltravioletABSTRACT
The binuclear cycloplatinated complex {[Pt(L)]2(mu-dppm)}2+ (1), where HL is a new cyclometalating ligand 2-phenyl-6-(1H-pyrazol-3-yl)pyridine, is found to behave as a molecular pivot-hinge in which the closing and opening of the hinge is effected by the reversible formation and cleavage of the Pt-Pt d8-d8 interaction and the intramolecular pi-pi interaction mediated by the protonation/deprotonation of the 1-pyrazolyl-NH on the cyclometalating ligand L.
ABSTRACT
[reactions: see text] [(Ph3P)CuH]6 effectively catalyzes the hydrostannation of activated alkynes with exclusive regioselectivity for alpha-stannation. Syn hydrostannation is observed exclusively for alkynoates. Anti or syn hydrostannation adducts are obtained as products for alkynone substrates.
ABSTRACT
Conjugate reduction of alkynones by stoichiometric [(Ph(3)P)CuH](6) or catalytic [(Ph(3)P)CuH](6) and polymethyl-hydrosiloxane proceeds to cyclization by an aldol reaction with tethered ketones to generate [small beta]-hydroxyenones with good diastereoselectivity.
