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The cooperative forces of aurophilic and hydrogen bonding have been used in the self-assembly of phosphine or diphosphine complexes of gold(I) with the thiolate ligands derived from 2-thiobarbituric acid, SC(4)H(4)N(2)O(2), by single or double deprotonation. The reaction of the corresponding gold(I) trifluoroacetate complex with SC(4)H(4)N(2)O(2) gave the complexes [Au(SC(4)H(3)N(2)O(2))(PPh(3))], 1, [(AuSC(4)H(3)N(2)O(2))(2)(micro-LL)], with LL = Ph(2)PCH(2)PPh(2), 2a, Ph(2)P(CH(2))(3)PPh(2), 2b, or Ph(2)PCH=CHPPh(2), 2c, or the cyclic complex [Au(2)(micro-SC(4)H(2)N(2)O(2))(micro-Ph(2)PCH(2)CH(2)PPh(2))], 3. In the case with LL = Ph(2)P(CH(2))(6)PPh(2), the reaction led to loss of the diphosphine ligand to give [Au(6)(SC(4)H(3)N(2)O(2))(6)], 4, a hexagold(I) cluster complex in which each gold(I) center has trigonal AuS(2)N coordination. Structure determinations show that 1 has no aurophilic bonding, 2b, 3, and 4 have intramolecular aurophilic bonding, and 2c has intermolecular aurophilic bonding that contributes to the supramolecular structure. All the complexes undergo supramolecular association through strong NH...O and/or OH...N hydrogen bonding, and complex 3 also takes part in CH...O hydrogen bonding. The supramolecular association leads to formation of interesting polymer, sheet, or network structures, and 4 has a highly porous and stable lattice structure.

Atomic layer deposition (ALD) of Nb 2 O 5 thin films was studied using three novel precursors, namely, t BuNNb(NEt 2 ) 3 , t BuNNb(NMeEt) 3 , and t amylN Nb(O t Bu) 3 . These precursors are liquid at room temperature, present good volatility, and are reactive toward both water and ozone as the oxygen sources. The deposition temperature was varied from 150 to 375 °C. ALD-type saturative growth modes were confirmed at 275 °C for t BuNNb(NEt 2 ) 3 and t BuNNb(NMeEt) 3 together with both oxygen sources. Constant growth rate was observed between a temperature regions of 150 and 325 °C. By contrast, amylNNb(O t Bu) 3 exhibited limited thermal stability and thus a saturative growth mode was not achieved. All films were amorphous in the as-deposited state and crystallized between 525−575 °C, regardless of the applied precursor and oxygen source. Time-of-flight elastic recoil detection analysis (TOF-ERDA) demonstrated the high purity of the films. Atomic force microscopy (AFM) revealed that the films were smooth and uniform. The films exhibited promising dielectric characteristics with permittivity values up to 60.

Treatment of fluorenone, 2,3-diphenylindenone, tetraphenylcyclopentadienone, or 2,5-diethyl-3,4-diphenylcyclopentadienone with ((trimethylsilyl)ethynyl)lithium gives, after hydrolysis, the analogous alkynol; subsequent addition of dicobalt carbonyl and then fluoroboric acid yields the corresponding fluorenyl, indenyl, or cyclopentadienyl cation stabilized by complexation to a tricarbonylcobalt moiety. Variable-temperature NMR data on these cluster cations, and on their bis(diphenylphosphino)methane derivatives, reveal that the barrier to migration of the cationic center between cobalt cluster vertices increases in the order fluorenyl < indenyl < cyclopentadienyl and suggest that the cations with more antiaromatic character have the greatest need for charge delocalization onto the metal center. Replacement of a Co(CO)3 cationic fragment by an Fe(CO)3 unit yields the mixed-metal species [((fluorenyl)CCSiMe3)FeCo(CO)6] (22) and [((2,3-diphenylindenyl)CCSiMe3)FeCo(CO)6] (27). In these structural models for the cationic complexes, the Fe−C(9) distance in 22 is 2.626(11) Å, while in the indenyl system 27 the Fe−C(1) distance is 2.347(7) Å, again indicating that the 8π indenyl cation interacts more strongly with the metal center than does the 12π fluorenyl cation.