Borides and Rhenides

Borides and Rhenides. The ternary complex boride UReB has been prepared and shown to have the ThMoB -type structure.  

The results of a computer analysis of binary Re intermetallic compounds with elements of the periodic system have been tabulated. This has enabled synthetic routes to new phases to be predicted.  

Co-ordination Chemistry.—Carbonyls. For a more comprehensive treatment of this topic the Specialist Periodical Report on Organometallic Chemistry should be consulted. 

The thermodynamics of a solid phase transition at 371 K for RejCCO) have been studied. Parameters found for H and AS, were 15.9 + 0.5kJmol and 

If Re(CO)5Br and Ag[AsF ] are stirred in liquid SOj for 20 hours at 298 K AgBr is precipitated, and after evaporation of excess SOj the complex [Re(C0)5(S02)][AsF ] is obtained. I.r. evidence suggests that the SOj ligand is bonded to the metal via the S atom, and that the Re—S bond is relatively weak. An analogous reaction between Re(CO)jBr and NSF3 in the presence of equimolar amounts of Ag[AsF ] results in quantitative formation of [Re(CO)5(NSF3)][AsF ] which is stable at 298 K. The 

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