RESUMEN
Three new neutral di-ferrocenyl-ethynylpyridinyl copper complexes, [L2(CuCl)2(PPh3)2] (), [L2(CuBr)2(PPh3)2] (), and [L2(CuI)2(PPh3)2] () were synthesized from the ferrocenyl-ethynylpyridine ligand (L) (), the appropriate copper halide CuX (with X = Cl(-), Br(-), I(-)) and triphenylphosphine. These neutral complexes were fully characterized by spectroscopic methods and by single crystal X-ray crystallography. Cyclic voltammetry in dichloroethane revealed chemically reversible ferrocenyl oxidation signals followed by characteristic "stripping reduction peaks" showing evidence for oxidation-product electro-crystallization. Scanning electron microscopy confirmed spontaneous formation of crystalline oxidation products with three distinct morphologies for X = Cl(-), Br(-), I(-). Energy dispersive X-ray elemental analysis data show Fe : P ratios of 1 : 2.0, 1 : 2.1 and 1 : 2.1 for electro-crystallization products of complexes , , and , respectively, indicating the presence of two [PF6](-) anions in the vicinity of the dioxidized complexes, and suggesting product formulae [](2+)[PF6](-)2, [](2+)[PF6](-)2 and [](2+)[PF6](-)2.
RESUMEN
The fabrication of solution-processed nontoxic mesoporous Bi2S3 structures is demonstrated and the suitability of these structures for use in hybrid solar cells investigated. Mesoporous Bi2S3 electrodes are prepared via thermal decomposition of a thin film composed of a bismuth xanthate single source precursor. The resultant Bi2S3 films are made up of regular needles with approximate dimensions of 50×500 nm, as confirmed by scanning electron microscopy (SEM). The crystallinity of the Bi2S3 is found to be dependent on the annealing temperature, as determined by X-ray diffraction. The porous Bi2S3 films are infiltrated with the hole conductor P3HT to generate novel hybrid films, and laser-based transient absorption spectroscopy is used to interrogate the charge-separation reaction at the resulting Bi2S3/P3HT heterojunction. Specifically, optical excitation of the hybrid films results in efficient and long-lived charge separation (microsecond to millisecond timescale), thereby rendering such films suitable for the development of novel low-cost solar-energy conversion devices.
RESUMEN
Three new tetra-ferrocenylethynylpyridinyl copper complexes, L4(CuI)4 (3), L4(CuBr)2 (4), and L4(CuCl)2 (5) have been prepared from the reaction of ferrocenylethynylpyridine (L)(2) with copper halides CuX (with X = I(-), Br(-), Cl(-)).The ligand 2 and the complexes 3-5 have been fully characterized by spectroscopic methods. The structures of 2-4 have been confirmed by single-crystal X-ray crystallography. 2 forms a dimer in the crystalline-state through C-H··N hydrogen bonds. 4 and 5 are dimers and 3 a tetramer, in all cases linked through Cu-X··Cu bridging interactions. Cyclic voltammetry in dichloroethane showed chemically reversible multiferrocenyl oxidation signals with evidence for product electro-crystallization. The oxidation products were isolated by electrodeposition onto a Pt disc electrode and investigated by scanning electron microscopy which confirmed the spontaneous formation of crystalline oxidation products with distinctive morphologies. Energy dispersive X-ray elemental analysis shows the presence of hexafluorophosphate (counterion) with the P:Fe ratio of 1:1, 0.5:1, and 1:1 for the electrocrystallized products 3, 4, and 5, respectively, suggesting the formulas [3](4+)(PF6(-))4, [4](2+)(PF6(-))2, and [5](4+)(PF6(-))4 for the electro-crystallized products.
RESUMEN
[Sn6 (O)4 (OSiMe3 )4 ] and [{Sn(OSiMe3 )2 }2 ] have been used to deposit SnO thin films by chemical vapour deposition. Films derived from [Sn6 (O)4 (OSiMe3 )4 ] comprise uniform cubes and are highly oriented, whereas those deposited from [{Sn(OSiMe3 )2 }2 ] are made up of a continuous non-oriented layer with oriented cubes on the surface. The structure of a co-crystal, 2 Sn6 (O)4 (OSiMe3 )4 â [Sn(OSiMe3 )2 ]2 â 4 THF, shows that [{Sn(OSiMe3 )2 }2 ], a liquid at room temperature, adopts a µ-OSiMe3 -bridged dimeric structure. [Sn6 (O)4 (OSiMe3 )4 ] reacts with O2 in a controlled manner to afford the novel oxo-cluster [Sn4( O)(OSiMe3 )8 ], the structure of which is reported. In addition, a crystal of {[Sn4 (O)(OSiMe3 )5 ]+ 2 [Sn(O)(OSiMe3 )4 Cl]+ 2 }[Cl]- 4 has been fortuitously isolated from the presence of SnCl2 in the starting material for the preparation of [Sn6 (O)4 (OSiMe3 )4 ], and has been shown to incorporate two novel cationic oxo-tin clusters.
RESUMEN
Sn(ii) derivatives of the aminoalcohols (t)Bu(H)NC(Me)(H)CH(2)OH (Htbap, ), (R(1)R(2)NCH(2))(2)C(H)OH (R(1) = R(2) = Me, , Hbdmap; R(1) = (t)Bu, R(2) = H, , Hbtbap), (R(1)R(2)NCH(2))(3)COH (R(1) = R(2) = Me, , Htdmap; R(1) = (t)Bu, R(2) = H, , Httbap) have been synthesised by reaction of the alcohol with Sn[N(SiMe(3))(2)](2). The structures of the ligands , .H(2)O, along with Sn(ttbap)(2) have been determined; the latter is pseudo-trigonal bipyramidal with nitrogen atoms in axial sites and oxygen atoms and a stereochemically-active lone pair in the equatorial positions. Sn(ttbap)(2) reacts with Fe(2)(CO)(9) in 2 : 1 ratio (Sn : Fe = 1 : 1) to afford the donor-acceptor complex (ttbap)(2)Sn:-->Fe(CO)(4), while in 1 : 1 ratio (Sn : Fe = 1 : 2) the Sn(0) complex (Httbap)Sn[Fe(CO)(4)](2) is formed, in which Httbap is a neutral zwitterionic form of the ligand. The structures of both bimetallic species are reported. Thermal decomposition of (Httbap)Sn[Fe(CO)(4)](2) under low-pressure CVD conditions gives a film containing a mixture of cubic-Sn, cubic-Fe and the hexagonal intermetallic phase Fe(3)Sn.