2145schematically shown in Figure 3, a simple reorientation of the copper square-pyramidal moieties might suffice, in principle, to bring about the dimer -+ uniform-chain transformation without any dramatic change in the geometry of the first coordination sphere around the metal centers or in the occupancy of space. An arrangement of dimers similar to that depicted in Figure 3 exists along the c axis of the title compound, and we also note that competition between neighboring copper atoms for bonding to apical chlorine atoms has been shown to be a relevant factor in determining the crystal chemistry of chloride-bridged chain compounds of copper(II).i6i8 In any event, the precise nature of the low-temperature phase of the present compound and the mechanism or reason for the postulated transition are interesting problems that remain open to further studies, particularly lowtemperature X-ray studies.In conclusion, the results presented in this paper confirm the utility of synthesizing new halide-bridged copper(I1) compounds with heterocyclic ligands as appropriate candidates for studying the impact of structural phase transitions on the magnetic int e r a c t i o n~.~~ As more of these types of systems are prepared and studied, it will hopefully be possible to provide some insight into the mechanisms that underlie the structural changes in them. This problem, of course, is also relevant to the family of distortion models typified by the spin-Peierls instability, Le., those in which changes in lattice energy and changes in exchange energy are of comparable magnitude.Registry No. Cu2L2CI2.2CH3OH, 120232-12-4; 8-aminoquinoline, 578-66-5; salicylaldehyde, 90-02-8. Supplementary Material Available:Tables SI-SIII, listing angles and distances associated with the aromatic rings, thermal parameters, and the derived hydrogen positions (3 pages); a table of calculated and observed structure factors (1 1 pages). Ordering information is given on any current masthead page. (35) See paper by L. J. de Jongh in ref 2a.[Au(dppm)],(BF,), is phosphorescent in solution ( A, , , = 593 nm, T = 21 ps, = 0.31). An SCF-Xa-SW molecular orbital calculation carried out on the model compound [Au(H2PCH2PH2)]?+ found the Au-Au u* HOMO to have 78% Au character. Of this, 41% is from the 6s orbital and 41% is from the 5d,z orbital. The metal-metal interactions are discussed. The 293-nm (e 21 OOO M-' cm-I) absorption band is attributed to a u(p,) -a*(s,dg) transition. The A d 2 emissive state appears to be "Ju*)(a) (C2h symmetry). The binuclear Ad2 compounds [A~(dppm)]~Cl~, [ A u ( C H~)~P P~~]~, [~-Bu,N],[Au(S,C=C(CN)~)],, [Au-(CH,P(S)Ph2)]2, and [AU(S~CNE~,)]~ are luminescent in the solid state at room temperature with A,, ranging from 465 to 593 nm and excited-state lifetimes ranging from 1 to 24 1 s . (Ph3PAu),(S2C=C(CN),) is luminescent at 77 K but not at room temperature. Mononuclear Ph3PAuCI luminesces in the solid state ( A, , , = 491 nm, 7 = 3 ps).
ChemInform Abstract The title complexes (III) and (V) form linear chain polymers with short metal-metal separations in the solid state. (III) crystallizes in P21/a with Z=4 and (V) in I2/a with Z=4. Both the compounds are strongly luminescent when irradiated with UV light. Luminescence is attributed to interactions between metal atoms in these compounds which are the first luminescent examples of this structural type. Studies of the solid of (V) by scanning electron microscopy indicate that fibers of (V) are either conducting or semiconducting.
Three clusters [Ag11(mu9-Se)(mu3-I)3{Se2P(OR)2}6] (R = Et, 1; iPr, 2; 2Bu, 3) were isolated from the reaction of [Ag(CH3CN)4](PF6), NH4[Se2P(OR)2], and Bu4NI in a molar ratio of 4:3:1 in CH2Cl2 in 47-55% yield. Compounds 1 and 2 can also be synthesized with high yield from the reaction of Ag10(Se)[Se2P(OR)2]8 with 8 equiv of Bu4NI. In the positive fast atom bombardment mass spectra of 1-3, two major peaks that correspond to the intact molecule with the loss of an iodide ion, [Ag11(mu9-Se)(mu3-I)(2){Se2P(OR)2}6]+, and a diselenophosphate ligand, [Ag11(mu9-Se)(mu3-I)3{Se2P(OR)2}5]+, were identified. Single-crystal X-ray analyses of 2 and 3 reveal an Ag11Se core stabilized by three iodide anions and six diselenophosphato ligands in a tetrametallic tetraconnective (mu2,mu2) coordination mode. The central core adopts the geometry of a 3,3,4,4,4-pentacapped trigonal prism with a selenium atom in the center. In addition, weak intermolecular Se...I interactions exist in 2 and form a one-dimensional polymeric chain structure. Furthermore, all compounds exhibit orange-red luminescence in both the solid state and solution.
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