We are reporting on the hydroxyalkyl appended arene ruthenium half sandwich complexes [( q(,-C6H5(CH 2)nOH} RuCI 2 ] (n = 2, 3) and the methyl ether of the hydroxypropyl derivative. Most sign ificantly, a structural comparison between the hydroxypropyl complex la and its methyl ether 2a revea ls, that the latter adopts the conventional dichloro bridged dimeric structure while la is a monomer. Coordinative saturation of the ruthenium centre is achieved by intramo lecu lar coord in ation of the appended hydroxy function, thus rendering the functiona lized arene an eight electron donor chelate ligand . The structure is further stabilized by in termo lecular OH·· ·CI hydrogen bridges between a terminal

Thioethers PhC 2 H 4 SMe, PhC 3 H 6 S i Pr and MeSAllyl form substitutionally labile monomeric adducts (p-cymene)RuCl 2 (SRR 0 ) (2a-c) upon treatment with the {(p-cymene)RuCl 2 } 2 dimer (p-cymene = g 6 -MeC 6 H 4 i Pr-1,4). Pure adducts were obtained by crystallization from CH 2 Cl 2 /Et 2 O, and 2a,c as well as the bis(thioether) complex ½ðp-cymeneÞRuClðSMe 2 Þ 2 þ SbF À 6 (3) were studied by X-ray crystallography. The trichloro bridged diruthenium complex ½ðp-cymeneÞRug 2 ðl-ClÞ 3 þ SbF À 6 is formed as a byproduct in the preparation of 3 and was also crystallographically characterized. In solution, pure samples 2a-c equilibrate with free thioether and the dimeric starting complex 1. The amount of 1 present in these mixtures increases with increasing bulk of the thioether substituents. Attempts to thermally replace the cymene ligand by the dangling arene substituent of the thioether ligand of 2a,b failed. Complexes 2a-c as well as the dimethylsufide derivative 2d were studied by cyclic voltammetry and display a close to reversible (2a,c,d) or partially reversible (2b) oxidation near +0.85 V and an irreversible reduction at rather negative potential. New peaks observed after oxidation and reduction point to dissociation of the thioether ligand as the main decomposition pathway of the associated radical cations and anions.

We report the highly selective assembly of unprecedented eta5-1-methylene-1,2-dihydronaphthalenide ligands from the stoichiometric coupling of a phenyl group and two equivalents of disubstituted propargylic alcohols; in this reaction, tetraphenylborate acts as a phenylating agent.

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