Lead(<scp>ii</scp>) soaps: crystal structures, polymorphism, and solid and liquid mesophases
作者:F. J. Martínez-Casado、M. Ramos-Riesco、J. A. Rodríguez-Cheda、M. I. Redondo-Yélamos、L. Garrido、A. Fernández-Martínez、J. García-Barriocanal、I. da Silva、M. Durán-Olivencia、A. Poulain
DOI:10.1039/c7cp02351k
日期:——
phases and mesophases. The crystal structures at room temperature of all of the members of the series are now solved, showing the existence of two polymorphic forms in the room temperature crystal phase, different to short and long-chain members. Only nonanoate and decanoate present both forms, and this polymorphism is proven to be monotropic. At higher temperature, these compounds present a solid mesophase
This disclosure provides for new catalyst systems and new methods for preparing and using the catalyst systems for generating a trimerization product. In an aspect, the new catalyst systems comprise a chromium carboxylate that is prepared by anhydrous metathesis. In another aspect, the catalyst system comprise a chromium carboxylate that is prepared by anhydrous metathesis and a metal pyrrolide compound. The catalyst systems imparts improved performance and/or reduced catalyst system cost to an olefin trimerization process.
This disclosure provides a process for making transition metal carboxylate compositions by combining in an polar aprotic first solvent a transition metal precursor and a Group 1 or Group 2 metal carboxylate under substantially acid-free and substantially anhydrous conditions, to generate a mixture comprising the transition metal carboxylate composition. Optionally, the transition metal carboxylate composition can be purified, for example, by substantially removing the first solvent provide a residue comprising the transition metal carboxylate composition, and also optionally, further by extracting the transition metal carboxylate composition from the residue with a non-coordinating second solvent to provide an extract comprising the transition metal carboxylate composition.
A composition for application to hair or scalp comprises component (A): at least one nucleic acid related substance selected from the group consisting of adenosine 3ʹ5ʹ-cyclic phosphoric acid, derivatives thereof, flavin adenine dinucleotide and salts thereof: or further component (B): at least one compound selected from the group consisting of fatty acids, alcohols and derivatives thereof, having an odd number of carbon atoms. The composition makes it possible to prevent graying of the hair and restore grayed hair to its natural color by applying it to hair or scalp.
A composition for application to hair or scalp comprises (A) at least one compound selected from the group consisting of (i) forskolin and derivatives thereof and (ii) peptides having a basic skeletal structure represented by the following general formula (I):
-P-Glu-His-Q-Arg-Trp-Gly-Lys- (I)
(wherein P represents an L-norleucine or L-methionine residue; Q represents a D- or L-phenylalanine residue; and Glu, His, Arg, Trp, Gly and Lys are L-glutamic acid, L-histidine, L-arginine, L-tryptophan, glycine and L-lysine residues respectively); or the component A and (B) at least one compound selected from the group consisting of aliphatic acids, alcohols and derivatives thereof having an odd number of carbon atoms. The composition for hair or scalp exhibits excellent effect of preventing graying of the hair and restoring grayed hair to its natural color upon externally applied to the scalp and is highly safe as regards to the possibility of causing skin damage. Therefore, the composition can be widely used in various forms capable of being externally applied to the scalp.