A. A. Eisenbraun, C. B. Purves
1960 Canadian journal of chemistry (Print)  
5.64X10-6 c.g.s.-e.m.u., 3.2 B.AII.; (Ph3P)ZNiBrz tert. BuBr, 5.37X1OP6, 3.4 B.i\lI.; and (Ph3P)?NiBr?(PhBr)z, 5.59XlOw6, 3.8 B.M. The high magnetic moment of the Ni2+ ion in the latter two suggests that distortion from a regular tetrahedral arrangement can be decreased by the presence of crystalline solvent. The distortion in the coinpounds (Ph3P)?NiX2 ( X = Cl, Br, I, and NO3) seems to be partially due to the steric requirement by the size difference between triphenylphosphine and halide ion.
more » ... T o compensate for such a steric effect in (Ph3P)?NiBrz two inolecules of brolnobenzene may be more suitable than one molecule of tert.butyl bromide. The appearance of blue tint in many cases of compounds of the types (Ph3P)ZNiXzY and (Ph3P)?NiX?Y2 may have soine correlation with rather sinall distortion from a regular tetrahedral arrangement. Early researches 011 the preparation and properties of glyoxylic acid were extensively reviewed by Debus (1) and by Hendriclcs (2) , who noted that the substailce occasionally yielded ill-defined rhombic crystals of a monohydrate when stored over a drying agent. I n 1925, Hatcher and Holden (3) used the electrochemical method to reduce oxalic acid, isolated barium glyoxylate, decomposed the latter with sulphuric acid, and prepared anhydrous glyoxylic acid for the first time as monoclinic crystals melting a t 98'. This result was questioned by He[~clriclcs (2) because oxalic acid monohydrate, a probable impurity, melted a t 99' and occurred as monoclinic crystals, and also because his attempts to repeat the crystallization of glyoxylic acid failed. Later workers oxidized tartaric acid or its esters with a glycol-cleaving agent, periodic acid or a periodate (4, 5, 6), lead tetraacetate (7) , or sodiuln perbismuthate (S, 9), but apparently restricted their interest to the preparation of various esters and metallic salts of glyoxylic acid. In the present worlc, tartaric acid was oxidized with aqueous periodic acid, by-product iodic acid was removed as the insoluble lead salt, and, after neutralization with barium hydroxide, crystalline barium glyoxylate dihydrate was recovered in high yield. A11 ionexchange resin eliminated the cations fro111 an aqueous solution ol this salt, and evaporation of the effluent left glyoxylic acid as a clear syrup which eventually crystallized. The lnelting point was 104-107°, with softening a t 94'. The replacement of periodic acid by sodium inetaperiodate in the above oxiclation, followed by the removal of iodate ion, left
doi:10.1139/v60-089 fatcat:2oxixcihxvfulfwlguamk5dxl4