The syntheses are reported for two novel Tb3+ heterotrimetallic cyanometallates, K-2[Tb(H2O)(4)(Pt(CN)(4))(2)]Au(CN)(2)center dot 2H(2)O (1) and [Tb(C10N2H3)(H2O)(4)(Pt(CN)(4))(Au (CN)(2))]center dot 1.5C(10)N(2)H(8)center dot 2H(2)O (2) (C10N2H8 = 2,2'-bipyridine). Both compounds have been isolated as colorless crystals, and single-crystal X-ray diffraction has been used to investigate their structural features. Crystallographic data (moxa, A = 0.71073 angstrom, T = 290 K): 1, tetragonal, space group P4(2)/nnm, a = 11.9706(2) angstrom, c = 17.8224(3) angstrom, V = 2553.85(7) angstrom(3), Z = 4; 2, triclinic, space group P (1) over bar, a = 10.0646(2) angstrom, b = 10.7649(2) angstrom, c = 17.6655(3) angstrom, alpha = 101.410(2)degrees,beta = 92.067(2)degrees, gamma = 91.196(2)degrees, V = 1874.14(6) angstrom(3), Z = 2. For the case of!, the structure contains Au2Pt4 hexameric noble metal dusters, while 2 includes Au2Pt2 tetrameric clusters. The clusters are alike in that they contain Au Au and Au Pt, but not Pt Pt, metallophilic interactions. Also, the discrete clusters are directly coordinated to Tb3+ and sensitize its emission in both solidstate compounds, 1 and 2. The Photoluminescence (PL) spectra of 1 show broad excitation bands corresponding to donor groups when monitored at the Tb3+ ion f-f transitions, which is typical of donor/acceptor energy transfer (ET) behavior in the system. The compound also displays a broad emission band at similar to 145 nm, assignable to a donor meta centered (MC) emission of the Au2Pt4 dusters. The :PL properties of 2 show a similar Tb3+ emission in the visible region and a lack of donor-based emission at room temperature; however, at 77 K a weak, broad emission occurs at 400 rim, indicative of uncoordinated 2,2'-bipyridine, along with strong Tb3+ transitions. The absolute quantum yield (QY) for the Tb3+ emission (D-5(4) -> F-7(1(J = 6-3))) in 1 is 16.3% with a lifetime of 616 mu s when excited at 325 nm. In contrast the weak MC emission at 445 nm has a quantum yield of 0.9% with a significantly shorter lifetime of 0.61 mu s. For 2 the QY value decreases to 9.3% with a slightly shorter lifetime of 562 mu s. The reduced QY in 2 is considered to be a consequence of (1) the slightly increased donor acceptor excited energy gap relative to the optimal gap suggested for Tb3+ and (2) Tb3+ emission quenching via a bpy ligand-to-metal charge transfer (LMCT) excited state.