Phosphorus chemical shifts are relative to phosphoric acid and not as stated. In compound ( 5 ) the phosphorus chemical shift of the P2C3 ring was omitted; it is +35.6 p.p.m.Typeset and printed by Black Bear Press Limited,

Treatment of 1,8-bis(diphenylphosphino)naphthalene (dppn, 1) with stoichiometric amounts of sulfur or selenium in toluene at 80°C selectively afforded the diphosphine monochalcogenides 1-Ph 2 P(C 10 H 6 )-8-P(:S)Ph 2 (dppnS, 2 a) and 1-Ph 2 P(C 10 H 6 )-8-P(:Se)Ph 2 (dppnSe, 2 b). The 31 P{ 1 H} NMR spectrum of 2 b showed an unusually large 5 J(P±Se) value, which indicates a significant through-space coupling component. The monosulfide acted as a bidentate P,S-ligand towards platinum(II) (3 a), whereas the corresponding monoselenide complex (3 b') lost elemental selenium with formation of the previously reported complex [PtCl 2 (dppn)-P,P'] (3). Treatment of dppnSe with [(nor)Mo(CO) 4 ] (nor = norbornadiene) led to formation of [(dppnSe)Mo(CO) 4 -P,Se] (3 b). Solutions of the latter slowly deposited Se with formation of [(dppn)Mo(CO) 4 -P,P'] (4) which was also obtained by independent synthesis from 1 and [(nor)Mo(CO) 4 ].All isolated new compounds were characterised by a combination of 31 P, 1 H, 13 C and 77 Se (2 b) NMR spectroscopy, IR spectroscopy, mass spectrometry and elemental analysis. Single-crystal X-ray structure determinations were performed for dppnSe (2 b), [PtCl 2 (dppnS)-P,S] (3 a), [(dppnSe)Mo-(CO) 4 -P,Se] (3 b) and [(dppn)Mo(CO) 4 -P,P'] (4). In 2 b steric effects cause the naphthalene ring to be distorted and force the phosphorus atoms by 65 and 59 pm to opposite sides of the best naphthalene plane. In the metal complexes 3 a, 3 b and 4 the phosphino-phosphinochalcogenyl systems act as bidentate ligands through the P and the chalcogen atoms. The naphthalene systems are again distorted. The two independent molecules of 4 differ in their conformations.Einfach oxidierte Schwefel-und Selen-Derivate von 1,8-Bis(diphenylphosphino)naphthalin: Synthese und Koordinationschemie Inhaltsu È bersicht. Die Umsetzung von 1,8-Bis(diphenylphosphino)naphthalin (dppn, 1) mit sto È chiometrischen Mengen Selen oder Schwefel in Toluol bei 80°C fu È hrte selektiv zu den Diphosphin-Monochalkogeniden 1-Ph 2 P(C 10 H 6 )-8-P(:S)Ph 2 (dppnS, 2 a) und 1-Ph 2 P(C 10 H 6 )-8-P(:Se)Ph 2 (dppnSe, 2 b). Das 31 P{ 1 H} NMR Spektrum von 2 b zeigte einen ungewo È hnlich groûen Wert fu È r 5 J(P±Se), der auf eine signifikante Wechselwirkung durch den Raum deutet (through-space coupling). Das Monosulfid fungierte als zweiza È hniger P,S-Ligand gegenu È ber Platin(II) (3 a), wa È hrend sich der entsprechende Komplex des Monoselenids (3 b') unter Abscheidung elementaren Selens schnell in den bekannten Komplex [PtCl 2 (dppn)-P,P'] (3) umwandelte. Die Umsetzung von dppnSe mit [(nor)Mo(CO) 4 ] (nor = Norbornadien) fu È hrte zur Bildung von [(dppnSe)Mo(CO) 4 -P,Se] (3 b). Aus Lo È sungen dieses Komplexes in Dichlormethan schied sich langsam elementares Selen ab, wobei sich [(dppn)Mo(CO) 4 -P,P'] (4) bildete. Letzterer Komplex konnte auch durch unabha È ngige Synthese aus dppn und [(nor)Mo(CO) 4 ] hergestellt werden. Alle isolierten neuen Verbindungen wurden durch eine Kombination von 31 P, 1 H, 13 C und 77 Se (2 b) NMR-Spektroskopie, IR...

The effect of selected crown ethers on the uptake of alkaline earth cations by sulfonic acid and diphosphonic acid-based cation-exchange resins from hydrochloric acid media is examined. The effect observed is shown to vary with the hydrophobicity of the crown ether. Water-soluble crown ethers enhance the sorption of certain cations, thereby improving the selectivity of the resin for other alkaline earths over calcium ion, an apparent result of a synergistic interaction between crown ether present in the resin phase and the ionic functional groups of the resin. In the presence of more hydrophobic crown ethers, a decrease in cation sorption is often observed, a result of the exclusion of the crown ether from the resin phase and the formation of cation-crown complexes in the solution phase. The result can be a reversal of the selectivity sequence ordinarily exhibited by the resin.

-, which contains a stereogenic phosphorus atom. With PdCl 2 (COD), only the centrosymmetric

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