Two Tb(III) complexes, [Tb(TETA)] − and [Tb(TETA)(phen)] − (TETA = 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetate and phen = 1,10-phenanthroline), were synthesized and their luminescence ( 5 D 4 ! 7 F J=0-6 transitions) and magnetic properties were examined. The photoluminescence (PL) quantum yield of [Tb(TETA)(phen)] − (Q = 0.47) was significantly higher than that of [Tb(TETA)] − (Q = 0.006).The dramatic increase (78×) in green luminescence was attributed to intramolecular energy transfer from phen to Tb(III). The energy transfer rate according to Dexter theory was found to be approximately 10 11 s −1 . The temperature dependence of the molar susceptibilities confirmed that the two complexes behave as paramagnets obeying the Curie-Weiss law. In addition, the field-dependent magnetization of the two complexes measured in the −70 to + 70 kOe range at T = 1.8 K fitted well with the Brillouin function with the following values: g eff = 1.5, μ B = 9.27 × 10 −21 emu, and J = 6. These results provide new insights into the development of lanthanide metal complexes with tetraaza Results and DiscussionPL and Excitation Spectra. Figure 1(a) shows the PL spectra of the powdered Tb(III) complexes taken at 10 K. The PL spectra at RT (not shown) were similar but weaker Article

The crystal structures of R3PAu[SC6H4C(=O)NH2-2], R = Et (1), Ph (2), and Cy (3) show linear coordination geometries for gold defined by sulfur and phosphorus atoms. Supramolecular aggregation via {...H-N-C=O}2 synthons lead to dimeric aggregates in each case. In (1) and (2), the aggregates are spherical, but steric effects exerted by cyclohexyl rings in (3) dictate a rodlike form; no Au...Au interactions were noted in the crystal structures. Solvent dependence in their NMR spectra is correlated with intra- and intermolecular hydrogen bonding. The compounds uniformly decompose under controlled conditions to give gold. The complexes excited by UV light produce strong blue-green luminescence. The configuration interaction singles (CIS) post-Hartree-Fock (HF) calculations for the compounds indicate that it is the charge transfer from the sulfur and pi-orbitals of SC6H4C(=O)NH2-2 to gold that produce the emission from gold. The assignment of the observed luminescence is presented in terms of the relaxed excited states of gold, in which the vibronic interactions for three p-orbitals of gold are taken into account.

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