The superconducting electronic states of Nd 1.85 Ce 0.15 CuO 4Ϫ␦ ͑NCCO͒ are studied by applying the phasesensitive capability of tunneling spectroscopy. Unlike the YBa 2 Cu 3 O 7Ϫ␦ cases, the conductance spectra measured on ͑100͒-, ͑110͒and ͑001͒-oriented surfaces showed V-shaped gap structures, and no zero-bias conductance peaks were observed even around steps on the surfaces. The present results reject the possibility of d x 2 Ϫy 2-wave and d xy -wave symmetries for the pair potential in NCCO. The experimental spectra are well fitted to theoretical curves of anisotropic s-wave symmetry with a large smearing factor.

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Dihydrochloride of a binucleating ligand, 1,5-diamino-3-pentanol (Hdpl·2HCl) has been synthesized by a new method in a high yield (>70%). This ligand forms 1 : 1 complexes with copper(II), Cu(dpl)X(X=BF4, ClO4, NO3, and Cl(H2O)). The cryomagnetic study of the copper complexes has shown that they are binuclear, and a strong antiferromagnetic interaction is operating between two copper ions. The binuclear structure seems to be quite stable even in aqueous solution. The 1 : 1 complex with nickel(II) was also isolated as tetraphenylborate, which was essentially diamagnetic. A planar binuclear structure similar to the copper complexes was assumed for this complex. Its absorption band at 29.8×103 cm−1 (ε=160) was attributed to the charge transfer transition from the bridging oxygen to the nickel similarly to the bands in the 25–29×103 cm−1 region usually observed for alkoxo-oxygen bridged binuclear copper(II) complexes. Some 2 : 1 copper(II)–dpl complexes have also been synthesized and characterized as binuclear complexes. 1,5-Bis(dimethylamino)-3-pentanol has been synthesized, and its 2 : 1 copper(II) complexes have been isolated.

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