From the NO-and 0,-dependence of the trapping rate of 1,6-cyclodecadiyne (3) in the gas phase and in supercritical C 0 2 in the temperature range 160-290°C, the enthalpy profile for the equilibrium 3 F? 4 has been established. For the diradical4, a heat of formation of 116.2 kcal . mol-I is obtained, which agrees well with the expectation value derived by the abstraction of two hydrogen atoms from hexahydronaphthalene (5).Gleiter and Ritter"] demonstrated recently that 1,6-cyclodecadiynes represent ideal model compounds with which to study the interaction of nonconjugated diynes. By means of trapping experiments using hydrogen donors of different reactivity (1,4-~yclohexadiene, 9,1O-dihydroanthracene, and cyclooctene), they obtained convincing evidence for an intermediate 1,4-diradical 2, when N,N'-diisopropyl-1,6-diazadeca-3,S-diyne (1) was heated to 100°C.

Coupling of methyl[4-(diphenylphosphino)benzyllamine to poly(acry1ic acid) and 4-(diphenylphos-phin0)benzaldehyde to polyethylenimine demonstrates a new method ofpreparing water-soluble phosphine ligands. The feasability of these polymeric ligands in complex formation is demonstrated by the preparation and characterization of water-soluble cobalt carbonyl complexes.Catalysis in biphasic media has emerged as an important method for achieving easier separation and reuse of homogeneous metal catalysts1 and its feasibility has been demonstrated by the Rhone-PoulendRuhrchemie hydroformylation process.2 The key prerequisite for carrying out homogeneous catalysis in aqueous solution is the use of a water-soluble ligand, a property usually achieved by functionalization of parent chiral or achiral, mono-or bidentate ligands with polar substituents, e.g.-OH , -COO-, -S03-, and -NRs+. While monosulfonated triphenylphosphine (TPPMS) marks a starting point in the development3 and application4 of watersoluble phosphine ligands, trisulfonated triphenylphosphine (TPPTS), with its extremely high water solubil-it^,^ can be regarded as the prototypical ligand in the field. Concomitant with improvements6 in the synthesis and purification of TPPTS, the coordination chemistry, as well as the catalytic chemistry, of TPPTS has pr~gressed.~ With respect to catalysis and coordination chemistry TPPTS complexes and their triphenylphos-

The following 14-membered ring diynes have been synthesized: cyclotetradeca-4,ll-diynone (4), cyclotetradeca-4,lldiyne-1,8-dione (6)-the corresponding exomethylene derivatives 5 and 7 , as well as 1,8-dioxacyclotetradeca-4,1l-diyne (8). The synthesis of the diketal of 4 was achieved by the reaction of the ethylene ketal of 1,5-dibromopentan-3-one (9) with the dilithium salt of 1,8-nonadiyne. Similarly, the diketal of 6 was prepared from the dilithium salt of the ethylene ketal of 1,8-nonadiyn-5-one 11 with 9. The unprotected ketones 4 and 6 were obtained by treating the ketals 10 and 14, respectively, with HC1. The ketones 4 and 6 were transformed to the exomethylene derivatives by a Wittig reaction. The reaction of the dilithium salt of 5-oxanona-1,8-diyne (16a) with 1,5-dibromo-3-oxapentane (15) yielded 8. X-ray investigations of single crystals of 6 and 8 revealed chair conformations with a zig-zag arrangement, employing two anti orientations of the two chains between the triple bonds. Azig-zag arrangement of the chain containing the carbonyl group was also found in 4. In 3b and 7 a Ci symmetry was found, with only one anti conformation in each chain. Molecule 6 crystallizes with C2h symmetry and 8 with a center of symmetry.Medium-sized cyclic diynes are useful models to probe the interactions between two triple bonds in close proximity. By means of photoelectron spectroscopy it was found that the interaction between the triple bonds depends considerably on the ring size"]. Structural investigations on cyclodeca-l,6-diyne (1) [2] and cyclohexadeca-1,lO-diyne (2)L3], showed that the uneven chains between the triple bonds tend to arrange in a zig-zag arrangement, such as to adopt a chair conformation. In the case of cyclotetradeca-1,8-diyne it was shown that the conformer 3b with two gauche interactions (instead of the zig-zag arrangement 3a) is favored in the solid ~t a t e [~.~J .In order to understand conformational effects of medium-sized rings better we synthesized cyclotetradeca-4,ll-diynone (4), 5-methylenecyclotetradeca-l&diyne (5), cyclotetradeca-4,11 -diyne-l$-dione (6), 5,12-dimethylenecyclotetradeca-l,8-diyne (7) and 1,8-dioxacyclotetradeca-4,ll -diyne (8). Synthesis of 4-8Our synthesis of 4 commenced with 1,5-dibromopentanand its transformation to the ethylene ketal 9. This compound then reacted with the dilithium salt of 1,8-nonadiyner7] to yield the ketal 10, which can be converted to 4 by treatment with 1.5 N HCl. A second path to 10 is the reaction of the dilithium salt of 11, l l a , with 1,5-diiodopentane. Both alternatives gave 10, but in low yields (7%). The synthesis of the diketone 6 also starts with 9. The reaction of 9 with two equiv. of lithium acetylide ethylenediamine adductrs] yields a mixture of 11 (300/), 12 (22%) and 13[8,9] (3%), which can be separated by fractional distillation. The reaction of the lithium salt l l a with 9 gives the diketal 14 which gives, after hydrolysis, the diketone 6 in 7% yield (Scheme 1).The ketones 4 and 6 were transformed to 5 and 7, respectively, by...

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