It~srir~ite for Mnte1.ici1.s Resc~nrc.11, MciMrister Utli~!ersit!,, H(l~,ril/ot~. O~rtnrio Received May 25, 1972 The compound previously reported as /I-ReOCI, has been shown by analysis and single crystal X-ray diffraction to be p-0x0-bis~oxotrichloro(0-perrhenyl chloride)rhenium(VI)}, (Re,0,C16)(Re03CI),. The crystals were triclinic, a = 6.1 12(5), b = 12.876(9), c = 6.020(5) A, a = 88.30(5), /I = 95.88(5), y = 105.36(5)", Pi(Cf, No. 2) 2 = I. Intensities were measured by a densitometer from photographs recorded on an integrating precession camera. The structure was refined by full matrix least squares to give a final R, of 0.072. The molecule is composed of a dimeric Re,03C16 unit with a bridging oxygen atom on the center of symmetry and an Re-0 (bridge) distance of 1.847(1) A. The remaining 0x0-group on each rhenium is cis to the bridge and is strongly bonded (1.69(2) A), and the position trans to the terminal 0x0-group is filled by a weak bond to an oxygen atom of a perrhenyl chloride molecule. The infrared spectrum of the compound has been explained in terms of the structure.Nous demontrons que le compost rapport6 prtctdemment comme ttant /I-ReOCI, est le p-oxo-bisjoxotrichloro(0-chlorure de perrhCnyl)rhtnium(VI)}, soit (Re,O,Cl6)(ReO,CI),, par analyse et diffraction de rayons-x d'un cristal unique. Les cristaux sont tricliniques, a = 6.1 12(5), b = 12.876(9), c = 6.020 (5) [Traduit par le journal] Ca~l;~dinn .lou1.11;11 ol'Cl~cmisl~~)~. 50, 3607 (1972)