Structure D 2000Hydrogen Bonding and Structure of Ba2Ru2Cl10O·10H2O. -The title compound precipitates from a solution of RuCl 3 ·3H 2 O and BaCl 2 in 50% aq. HCl. Ba2Ru2Cl10O·10H2O crystallizes in the monoclinic space group C2/c with Z = 4 (single crystal XRD). The structure consists of alternating layers of [Ru2Cl10O] 4and [Ba(H2O)7] 2+ ions. The overall structure is held together by O-H···O hydrogen bonds and O-H···Cl dipole-dipole interactions. -(BOUFAS*, S.; HADJADJ, N.-E.; MERAZIG, H.; MOLITERNI, A. G.; ALTOMARE, A.; Acta Crystallogr., Sect. C: Cryst. Struct. Commun. 63 (2007) 8, i60-i62; Lab. Chim. Mol., Univ. Mentouri, 25000 Constantine, Algeria; Eng.) -Schramke 45-005