characterized spectroscopically. On the basis of the 360-MHz H-NMR and 90-MHz "C-NMR spectral4] and the result of decoupling experiments the trimers were assigned to the structures la and l b . In both isomers the cyclopentene ring bound to the norbornane system is oriented in the endo position. A n l a l b Ill a) J . Falbe, U. Hasserodt: Katalvsaforen. Tenside und Mineralolodditiue.

SummaryThe title cation ( = Ni,L:) is formed in a variety of reactions (Schemes 1 and 2) in systems containing Ni2+ and (2-thiolatoethyl)-diphenylphosphine ( = L-) in the absence of coordinating anions at Ni2'/L-ratios > 0.5 in apolar or moderately polar media. Introduction. -Thiolate donors coordinated to one metal ion are characterized by their strong residual nucleophilicity which enables them to act as bridging ligands to a second metal centre. Owing to the important role of polynuclear metal thiolato complex structures in biological systems, their chemistry has been developed rapidly in the last few years and has been reviewed recently [I]. More specifically, polynuclear com-

Der durch l :′2‐molare Umsetzung von hydratisiertem Ni‐nitrat und 2‐Mercaptoethyl‐diphenylphosphin synthetisierte neutrale trans‐Komplex (I) reagiert mit hydratisiertem Ni‐perchlorat (Verhältnis 3:1) zu dem als Perchlorat oder Tetraphenylborat isolierten Titelkomplexkation (ll).

Am Beispiel des chiralen Phosphins (I) wird gezeigt, daß diastereomere Wechselwirkungen zwischen Enantiomeren in einer Probe für die Bestimmung des Enantiomerenüberschusses genutzt werden kön‐.