IR Spectra, Magnetic and Thermal Studies of Copper (II) Complex of N-Hydroxy-N-(4-Chloro) Phenyl N’(4-Fluoro) Phenyl Benzamidine Hydrochloride

Copper (II) reacts with HCPFPBH and forms buff coloured precipitate insoluble in many organic solvents like absolute alcohol, ether, benzene, chloroform etc. The Solid complex has molecular formula (C19H13N2OFCl)2Cu which melts at 2020C with decomposition. The infrared spectra of the complex was recorded in the range 4000-450cm-1. The ligand molecule consists of a weak band at 2550 cm-1. This confirms the presence of azomethine nitrogen in the ligand. This band is absent in the IR Spectrum of the complex confirming the involvement of this group in complexation . The strong band of the ligand at 1640 cm-1 is due to C = NH+ group which shifts to lower frequency by 60 cm-1. This confirms the formation of C = N -----Cu bond. The N – O stretching mode shifts to higher frequency from 930 cm-1 to 960 cm-1 this confirms the formation of N – O – Cu bond by replacement of N – O – H proton by Copper.Cu – N band appears at 460 cm-1 which supports the formation of Cu – N bond. The positive value of volume susceptibility confirms that the complex is paramagnetic. TGA studies suggest that complex is thermally stable upto 2020C and melts with decomposition. At this temperature water molecules are absent which is also suggested by IR spectra of the complex. These studies support the use of N-Hydroxy-N-(4-Chloro) phenylN’-(4-Fluoro) phenyl benzamidine hydrochloride for gravimetric determination of Copper (II) in ores and alloys.

The occurrence of pituitary prolactin depletion–transformation in lactating rats: dependence on strain of rats, homogenization conditions and method of assay

ABSTRACT The objectives of this study were to determine (1) whether pre-release transformation (depletion) of pituitary prolactin occurs as the result of suckling to the same extent in several strains of lactating rats, (2) the molecular nature of the transformed hormone, (3) whether the quantity of transformed (depleted) prolactin recovered is dependent upon the type of homogenization buffer used and (4) whether the method of assay influences the extent to which transformed prolactin is detected. During the course of these experiments other factors such as the methods of handling and storing pituitaries and homogenates were also found to influence the amount of prolactin recovered. The results indicated that transformation of prolactin is a very labile event which is affected by many factors. Strain and supplier of rats was critical to the observation of suckling-induced depletion of prolactin, with Spartan- and Holtzman-derived Sprague–Dawley strains exhibiting the most consistent responses. When transformation was observed, it mattered little which buffer was used for homogenization; however, alkaline or acidic buffers extracted more prolactin than did neutral buffers. Triton X-100 also significantly enhanced the efficiency of extraction by neutral buffers. Maintaining pituitaries on dry ice immediately upon removal from the animal increased the amount of prolactin recovered, as did freezing the homogenate for 1–5 weeks before assay. The addition of the protease inhibitor, benzamidine hydrochloride, did not affect the pituitary content of prolactin. Assay of prolactin by polyacrylamide electrophoresis and densitometry yielded more prolactin than either radioimmunoassay or the Nb2 lymphoma bioassay. The molecular nature of pituitary prolactin, extracted at neutral pH, as judged by gel filtration was altered slightly but consistently by suckling, such that large molecular forms increased at the expense of the smallest molecular form. We conclude from these studies that great care must be exercised when attempting to characterize dynamic changes in pituitary prolactin content in lactating rats. Strain and supplier of rats, methods of handling and storing pituitaries, types of buffers used for homogenization and methods of assay all influence the amount of prolactin recovered and can influence the extent to which rapid changes in pituitary prolactin are detected. J. Endocr. (1987) 113, 71–80