Institute of Inorganic Chemistry

Synthesis of a novel tricyclic 1,4-diphosphinine I and, subsequently, of a stable anionic 1,4-diphosphinine II is reported; while II can be used as precursor for 1,4-disubstitution products, its oxidation leads to the formation of the P–P coupling product III.

A facile synthetic methodology is reported that permits access to the backbone (Et 2 N) 2 P-substituted thiazol-2-thione 2 [(Et 2 N) 2 P-THS Me ; THS Me = 3-methylthiazol-2-thione-5-yl]. Starting from 2, Et 2 N(Cl)P-substituted thiazol-2-thione 3 [Et 2 N(Cl)P-THS Me ] was formed using chloride scrambling with PCl 3. Subsequently, nucleophilic substitution using Ph 2 CHLi afforded [Et 2 N(Ph 2 CH)P-THS Me ] (4) which, via reaction with PCl 3 , afforded [Ph 2 CHP(Cl)THS Me ] (5). Conversion of 4 into phosphaalkene [Ph 2 C=P-THS Me ] (6) was achieved, but its thermal instability precluded isolation. Complex [κP-W(CO) 5 {Ph 2 CH(Cl)P}-THS Me ] (7) was then synthesized and used to access end-on

Grapefruit is source of anticancer and antioxidant reagents. Extracts of grapefruit peel (Gf-P) and seeds (Gf-S) were screened for their antioxidant capabilities at room temperature to stabilize soybean and sunflower oil for a storage period of 45 days. b-carotene linoleic acid system, FRAP assay, ABTS method were performed for the measurement of antioxidant potential of Gf-P and Gf-S. Oil samples containing extracts of Gf-P and Gf-S at 400 ppm, 800 ppm, 1200 ppm concentrations as well as synthetic antioxidants (BHT and BHA) at 200 ppm concentration were prepared. Free fatty acid (%) and peroxide (meq/Kg) values of all these prepared samples were evaluated. Results were statistically analyzed and it was observed that Gf-P has better antioxidant potential than Gf-S.

Diels–Alder-reactions of a thiazol-2-thione-based, tricyclic 1,4-diphosphinine were investigated, showing that the central aromatic π-system can react with various dienophiles. In one case, photochemical deprotection of the 1,4-diphosphinine was found.

Sixty apparently fresh and properly iced samples of fish species were randomly collected from five major markets of Punjab, Pakistan. These samples were transported to the Fish Quality Control Laboratory, FR&TI, Lahore kept in ice boxes and temperatures below -1 oC. The samples were examined for Physical Parameters including Appearance, Glazing, Texture, Odour, Presence of Black Spots and Chemical Parameter including determination of Histamine levels by LCMS/MS. All Physico-Chemical Parameters were found within normal range. Histamine was either not detected or found within permissible limits as compared with International Standards for human consumption. In conclusion, significant decomposition and histamine formation can be avoided by good fish handling practices including icing or rapid immersion of the catch in chilled water followed by uninterrupted frozen storage.

A facile synthetic protocol enables the synthesis of the 4‐phosphanyl‐5‐thiophosphanoyl thiazole‐2‐thione 1 through the selective lithiation of the 5‐thiophosphanoyl thiazole‐2‐thione VIb followed by reaction with chlorodiphenylphosphane. The reaction of 1 with elemental sulfur leads to the PV/PV homochalcogenide thiazole‐2‐thione 2. The heterochalcogenide thiazole‐2‐thione 4 was obtained through the reaction of PIII/PV‐substituted thiazole‐2‐thione VIb with H2O2–urea. All compounds were characterized by 31P, 1H, and 13C NMR spectroscopy, IR spectroscopy, elemental analysis, mass spectrometry, and single‐crystal X‐ray diffraction studies.