Coordination of alcohols and carbohydrate oxygen to a transition metal centre can result in many processes: formation of stable complexes via alcohol functionality (1); oxidfition of an alcohol, provided a metal complex is an oxidant (2), and oxidative addition of a R C H 2 0 H bond (3) to the metal. One can envisage, that oxidative addition of a R C H z O H bond will also begin with oxygen coordination producing a transient species. Ruthenium(IV) can be regarded as an interesting centre, being electrophilic but still possessing oxidizable electrons. We planned to identify such a species by oxidation of commercial ruthenium(III) chloride. In this communication we report preliminary observations concerning coordination of carbohydrates and alcohol to the newly synthesized Ru2OC16[NCMe] 4 (1) complex. Commercial ruthenium chloride [Aldrich: 35.6% Ru; 45.5% C1; 23.5% H 2 0 (0.13 g) in MeCN (15 cm 3) (spectral purity)] was boiled under reflux in air for 75 rain. The warm solution was filtered and the filtrate cooled to room temperature and then refrigerated ( 5 ~ Brown-black crystals precipitated after ca. 24h (yield 32-36%). The identity of this material was established by an X-ray study. Crystals subjected to structure determination had the following analysis (Found: C, 20.9; H, 2.7; N, 12.9; Ru2OC16[NCMe]g(MeCN)2 , C12Hx8Nz6C16ORu2 calcd: C, 21.3; H, 2.65; N, 12.4%). Some crops of crystals differed in composition from the formula RuzOC16[NCMe]4(MeCN)2 probably because of variable amounts of acetonitrile of crystallization. The i.r. spectra were taken in KBr and in Nujol mull. I.r. Vmax(Cm x): (2974, 2914) vs, (2326, 2298) vs, (1406, 1366) m, (1029, 954) m, 486 s, 407 w. XH-n.m.r. (200 MHz, D20 ) 2.05 s, 2.21 s ten times weaker than 2.05. Figure 1 shows the molecular structure of (1). Crystal data for (I): C12H18N6C16ORuz.M = 653.15, monoclinic, space group C2/m, a = 14.688(4), b = 10.448(3), 3 c = 8.241(2) ~; fl = 96.84(1), v= 1255.67~, F(000)= 879, Z = 2, D c = 1.727523 gcm3 total number of reflections 1776, R(F)=0.0235 and Rw(F)=0.025, wavelength =0.71069/~. A crystal ca. 0.25 x 0.25 • was mounted on a glass fibre and transferred to a goniostat. The data collection was made at -173 ~ using the standard moving crystal, moving detector technique with fixed background counts at each extreme of the scan. Data were corrected for Lorentz and polarization terms and