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Comparison of 8-Methylquinoline and Benzo[h]quinoline Complexes of Palladium(i1) with Those of Related Ligands. Crystal and Molecular Structure of Aqua( benzo[h]quinoline) [2-(dimethylaminomethyl)phenyl-N]palladium(ii) Perchlorate t

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Reactions of cis-[PtCI,(PMe,Ph),] with terminal alkynes RC,H (R = Ph or But) and diethylamine in the presence of CuCl (up to 0.35 rnol per rnol Pt) yielded the complexes cis-[ PtCuCI(C,R),( PMe,Ph),]. The crystal structure for R = But showed that both alkynyl ligands are (J bonded to Pt and q2 co-ordinated to the Cu which has an approximately trigonal-planar geometry. The Pt( C,R),CuCI system is distorted from planarity. Similar reactions, but with more CuCl (1 rnol per rnol Pt), led to trans-[P~CU,CI,(C,R),(PM~,P~)~] (R = But). Treatment of the compound [Pt(C,Ph),(dppe)] (dppe = Ph,PCH,CH,PPh,) with [Cu(MeCN),] [BF,] gave [PtCu(MeCN)(C,Ph),(dppe)] [BF,] which is believed t o be structurally analogous to the neutral chloro complex. An acetone-acetonitrile solution of this complex deposited crystals of [Pt,Cu(C,Ph),(dppe),] [ BF,]. The crystal structure of the latter contains orthogonal platinum co-ordination planes and each of the four alkynyl ligands is q2 coordinated to a Cu atom in an approximately tetrahedral environment involving only carbon. Alkynyl ligands can bridge metal centres in many ways. ' Even bridging between two metal atoms occurs in three distinct modes, A-C. There are many examples of mode A, which can be regarded as the standard form when both metal atoms are transition metals. Mode B is much less common; it has been found for aluminium s y ~t e m s ~. ~ and we have identified an example recently in a triosmium c l u ~t e r . ~, ~ The symmetrical form C is also fairly uncommon; the cluster [Ru,(p-C,Bu')-

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The cluster [Ru3(CO)12] normally reacts readily with tertiary phosphines and diphosphines in the presence of Me3NO to give simple phosphine-substituted derivatives by a reaction involving nucleophilic attack of the amine oxide at CO leading to CO2 formation. However, the corresponding reaction of [Ru3(CO)12] with (R)-BINAP [2,2‘-bis(diphenylphosphino)-1,1‘-binaphthyl] in the presence of Me3NO does not give [Ru3(CO)10(BINAP)], as expected, but instead an 80% yield of the dihydroxy complex [Ru3(μ-OH)2(CO)8{μ-(R)-BINAP}] (1) as the first example of a μ-BINAP complex. NMR coalescence effects are observed in the 1H NMR spectra, but by using a 13CO-enriched sample, we were able to show that the fluxionality is not cluster-centered since the 13C{1H} NMR spectrum for the CO ligands is invariant over a wide temperature range. COSY spectra were used to show that there is restricted rotation about two of the four P−Ph bonds while the other two are rotating freely. From a single-crystal XRD study it can be seen that two Ph groups are unimpeded while the other two are closely aligned to the naphthyl rings in a graphitic manner and it is this that leads to the restricted rotation. This bridging ligand adopts quite a different conformation about the C−PPh2 bonds to that in free BINAP, the structure of which was also determined for comparison, and somewhat different from that in known chelating BINAP complexes. In contrast, the direct thermal reaction of (R)-BINAP with [Ru3(CO)12] in octane gives, in addition to traces of two uncharacterized species, a 38% yield of the cluster [Ru3(μ-H){μ-(R)-BINAP-H}(CO)9] (2), in which we believe that ortho metalation has occurred at one of the four Ph rings to form the first example of a cyclometalated BINAP ligand. We have been unable to obtain simple derivatives such as [Ru3(CO)11(BINAP)] or [Ru3(CO)10(BINAP)], although we have shown that the osmium analogues may be synthesized.