Search

C103H116O13SiSn4, triclinic, P1‾$\overline{1}$ (no. 2), a = 14.8676(4) Å, b = 17.6664(4) Å, c = 20.8357(6) Å, α = 106.430(2)°, β = 107.192(2)°, γ = 100.898(2)°, V = 4787.5(2) Å3, Z = 2, Rgt(F) = 0.0325, wRref(F2) = 0.0845, T = 150 K.

C103H116O13SiSn4, triclinic, P 1 ‾ $\overline{1}$ (no. 2), a = 14.8676(4) Å, b = 17.6664(4) Å, c = 20.8357(6) Å, α = 106.430(2)°, β = 107.192(2)°, γ = 100.898(2)°, V = 4787.5(2) Å3, Z = 2, R gt (F) = 0.0325, wR ref (F 2) = 0.0845, T = 150 K. [ABSTRACT FROM AUTHOR]

Stannyl-substituted [(RZn)4(OR′)4] cubanes with different tin-containing alkoxy groups [Ph3SnOZnMe] ( 1), [Ph3SnOZnEt] ( 2), [Me3SnOZn tBu] ( 3), and [Ph3SnOZn tBu] ( 4) are easily accessible by Brønsted acid-base reaction of the corresponding triorganotin hydroxides with ZnMe2, ZnEt2, and Zn( tBu)2, respectively. All new compounds 1- 4 were characterized by various spectroscopic methods and the structures of 1 and 3 were confirmed by single-crystal X-ray diffraction analysis. The thermal degradation of the precursors 1-4 under dry synthetic air (20 % O2, 80 %N2) was studied and the final oxide materials were characterized by employing powder X-ray diffraction (PXRD) analysis, inductively coupled plasma-optical emission spectrometry (ICP-OES), transmission and scanning electron microscopy (SEM and TEM), energy dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). Remarkably, compounds 1 and 2 proved to be suitable as single-source precursors (SSPs) for the efficient preparation of tin-doped ZnO nanoparticles with tunable tin concentrations as a promising system for steering and improving the optoelectronic properties of tin-doped ZnO. Using 3 as SSP furnishes tin-containing ZnO materials with good electron mobilities at relatively low processing temperatures (350 °C) for thin-film transistor (TFT) applications. All the thin films of tin-doped ZnO prepared by spin-coating on silicon wafers are of great homogeneity and amorphous structure, which is promising for future applications in the field of transparent conducting oxides (TCOs). [ABSTRACT FROM AUTHOR]

The syntheses, structural characterization, and thermal degradation of a series of the new indium and gallium siloxide dimers [{Me2In(OSiEt3)}2] ( 1), [{Me2Ga(OSiEt3)}2] ( 2), [{Me2In(OSi(O tBu)3)}2] ( 3), [{Me2Ga(OSi(O tBu)3)}2] ( 4), and In[OSi(O tBu)3)] ( 5) is reported. Compounds 1- 4 are readily accessible by facile Brönsted reaction of InMe3 or GaMe3 with the corresponding silanols Et3SiOH and ( tBuO)3SiOH, respectively. Compound 5 could be obtained by analogous protolysis of [In{N(SiMe3)2}3] with an excess amount of ( tBuO)3SiOH. The suitability of 1- 5 to serve as molecular precursors for low-temperature synthesis of amorphous indium and gallium oxide for electronic applications was probed. Thus their thermal degradation was studied by Thermogravimetric/differential thermogravimetry analysis (TGA/DTG). Compounds 1- 4 were decomposed under dry synthetic air (20 % O2, 80 % N2) at low temperature to yield amorphous indium oxide and gallium oxide particles, respectively. In contrast, thermal degradation of 5 affords amorphous indium silicate. All of these products were analyzed by multiple techniques including powder X-ray diffraction analysis (PXRD), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). Thin-film field-effect transistors (FETs) could be fabricated through spin-coating of silicon-wafers with solutions of 1 in toluene and subsequent calcination under dry synthetic air at 350 °C. These films exhibit very good FET performance with a field-effect mobility of 3.0×10−1 cm2 V−1 s and an on/off current ratio of 108. [ABSTRACT FROM AUTHOR]

The syntheses and structural elucidation of dimeric [Sn(OCyHex)2] ( 1), its corresponding (cyclohexoxy)alkalistannates(II) [{M(OCyHex)3Sn}2] (M=Li ( 2), Na ( 3), K ( 4)), and of the first heteroleptic heterotermetallic Li/In/Sn-haloalkoxide clusters [X2In{LiSn2(OCyHex)6}] (X=Br ( 5), Cl ( 6)) with a double seco-norcubane core are reported. They represent suitable precursors for new amorphous indium tin oxide (ITO) materials as transparent conducting oxides with drastically reduced concentrations of expensive indium, while maintaining their high electrical performance. In fact, compounds 5 and 6 were successfully degraded under dry synthetic air at relatively low temperature, resulting in new semiconducting tin-rich ITOs homogeneously dispersed in a tin oxide/lithium oxide matrix. The obtained particles were investigated and characterised by different analytical techniques, such as powder XRD, IR spectroscopy, SEM, TEM and energy-dispersive X-ray spectroscopy (EDX). The analytical data confirm that the final materials consist of tin-containing indium oxide embedded in an amorphous tin oxide matrix. The typical broadening and shift of the observed indium oxide reflections to higher 2 θ values in the powder XRD pattern clearly indicated that tin centres were successfully incorporated into the In2O3 lattice and partially occupied In3+ sites. Investigations by EDX mapping proved that Sn was homogeneously distributed in the final materials. Thin-film field-effect transistors (FETs) were fabricated by spin-coating of silicon wafers with solutions of 5 in toluene and subsequent calcination under dry air (25-700 °C). The FETs prepared with precursor 5 exhibited excellent performances, as shown by a charge-carrier mobility of 6.36×10−1 cm2 V−1 s (calcination at 250 °C) and an on/off current ratio of 106. [ABSTRACT FROM AUTHOR]

Two new complexes, [Cd2(4-4′-bpy)2(pa)4] n ·0.25H2O ( 1) (pa = phenylacetate), and [Mn(4-4′-bpy)2(pa)(H2O)3]ClO4·2H2O, ( 2), have been obtained from hydrothermal reaction of Cd(NO3)2·4H2O and Mn(ClO4)2·6H2O with a mixture of the ligands, 2-phenylmalonic acid (2-phmalH2) and 4-4′-bipyridine (4-4′-bpy). The pa is formed in situ by decarboxylation of phenylmalonic acid. These complexes have been characterized by elemental analysis, FT-IR spectroscopy, thermogravimetric analysis and single-crystal X-Ray diffraction. The Cd(II) center is seven-coordinate and linked via pa ligands to form a binuclear complex in the asymmetric unit of 1. A ladder-like 1D chain of binuclear units is formed by Cd(II)–N coordination bond through 4-4′-bpy ligands. Complex 2 consists of a mononuclear manganese center based on a distorted octahedral geometry and exhibits a supramolecular structure containing hydrogen bonds and extensive π···π and C–H···π interactions. [ABSTRACT FROM AUTHOR]

Heterobimetallic drive and cooperativity lead to a striking scenario for C–H bond activation and heteroaggregation involving MoIIIdimers. Reaction of (RO)3MoMo(OR)3with molar excess of ZnMe2at–78 °C affords the novel mixed Zn, Mo oxo clusters [Mo2(MeZn)6(μ2-Me)(μ3-CH2)2(OR)7] 1(R = neopentyl) and 2(R = cyclohexyl) preserving the MoMo triple bond, while the same reaction performed at ambient temperature gives rise to the related cluster [Mo2(MeZn)6(μ2-CH2)(μ3-CH2)2(OR)6] 3. These complexes represent the first examples of heterobimetallic MoMo complexes with bridging methyl and methylene groups and agostic C–H→Mo interactions, as well as penta-coordinate carbon. The complexes 1–3were characterized by elemental analyses, multinuclear NMR and single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

A convenient and efficient synthesis of the stable monolithium alkylzinc alkoxo cubanes {Li(thf)(RZn)3(OR')4} [R = Me, R' = iPr (1), tBu (2); R = Et, R' = iPr (3), tBu (4)] is reported. They are well soluble in organic solvents and suitable molecular precursors for the formation of Li-containing ZnO nanoparticles. The compounds are accessible by a convenient one-pot reaction of the respective dialkylzinc with lithium alkoxides in the presence of water and can be isolated as white solids in 35-50% yield. Higher yields (80-85%) for 1 and 3 can be achieved by applying excess iPrOH instead of H2O as protolysis source. The compounds 1-4 were characterized by elemental analyses, multinuclear NMR and FT-IR spectroscopy, and single-crystal X-ray diffraction analysis (1 and 2). Interestingly, thermal treatment of solutions of 1 and 2, respectively, in anhydrous benzyl alkohol at 190 °C yields pure and highly crystalline Li-containing ZnO nanoparticles as evidenced by powder X-ray diffraction analysis (PXRD), Transition Electron Microscopy (TEM), FT-IR and 7Li MAS NMR spectroscopy. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of the first heterobimetallic methylzinc-magnesium alkoxide clusters [Me(6)MgZn(6)(OR)(8)] [R=Et (1 a), n-Pr (1 b), nBu (1 c)] with a bis-cubane-shaped MgZn(6)O(8) core is described. The thermal degradation of 1 a-c and mixtures of 1 a and the homometallic MeZn-alkoxide cubane [{MeZnOtBu}(4)] (2) in dry synthetic air led to wide-band-gap semiconducting Mg(x)Zn(1-x)O nanoparticles at temperatures below 500 °C. The final materials were characterized by different analytical techniques such as PXRD, REM, TEM, EDX, and IR spectroscopy. The morphology of the as-prepared magnesium-containing ZnO samples is influenced by the different organo groups (alkoxo) in the precursors. EDX mapping showed that magnesium is uniformly distributed in the ZnO matrix. The incorporation of magnesium led to a distortion of the ZnO lattice with increased a axis and decreased c axis parameters. Room-temperature photoluminescence (PL) spectra reveal that the near-band-edge (NBE) emission of Mg(2+)-doped ZnO is shifted to higher energies relative to that of pure ZnO., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Heterobimetallic drive and cooperativity lead to a striking scenario for C-H bond activation and heteroaggregation involving Mo(III) dimers. Reaction of (RO)(3)Mo[triple bond]Mo(OR)(3) with molar excess of ZnMe(2) at-78 degrees C affords the novel mixed Zn, Mo oxo clusters [Mo(2)(MeZn)(6)(mu(2)-Me)(mu(3)-CH(2))(2)(OR)(7)] 1 (R = neopentyl) and 2 (R = cyclohexyl) preserving the Mo[triple bond]Mo triple bond, while the same reaction performed at ambient temperature gives rise to the related cluster [Mo(2)(MeZn)(6)(mu(2)-CH(2))(mu(3)-CH(2))(2)(OR)(6)] 3. These complexes represent the first examples of heterobimetallic Mo[triple bond]Mo complexes with bridging methyl and methylene groups and agostic C-H-->Mo interactions, as well as penta-coordinate carbon. The complexes 1-3 were characterized by elemental analyses, multinuclear NMR and single-crystal X-ray diffraction analysis.

A convenient and efficient synthesis of the stable monolithium alkylzinc alkoxo cubanes {Li(thf)(RZn)(3)(OR')(4)} [R = Me, R' = (i)Pr (1), (t)Bu (2); R = Et, R' = (i)Pr (3), (t)Bu (4)] is reported. They are well soluble in organic solvents and suitable molecular precursors for the formation of Li-containing ZnO nanoparticles. The compounds are accessible by a convenient one-pot reaction of the respective dialkylzinc with lithium alkoxides in the presence of water and can be isolated as white solids in 35-50% yield. Higher yields (80-85%) for 1 and 3 can be achieved by applying excess (i)PrOH instead of H(2)O as protolysis source. The compounds 1-4 were characterized by elemental analyses, multinuclear NMR and FT-IR spectroscopy, and single-crystal X-ray diffraction analysis (1 and 2). Interestingly, thermal treatment of solutions of 1 and 2, respectively, in anhydrous benzyl alcohol at 190 degrees C yields pure and highly crystalline Li-containing ZnO nanoparticles as evidenced by powder X-ray diffraction analysis (PXRD), Transition Electron Microscopy (TEM), FT-IR and (7)Li MAS NMR spectroscopy.