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731.
732.
The crystal structure of the mixed oxide InGaO3(ZnO)4 has been determined from electron diffraction and single‐crystal X‐ray diffraction data. The compound crystallises in a hexagonal space group (P63/mmc; No. 194), deduced from convergent beam electron diffraction (CBED). Single crystals of InGaO3(ZnO)4 were grown from a K2MoO4 flux in sealed platinum tubes. Single crystal structure refinement from XRD data [a = 3.2850(2) Å; c = 32.906(3) Å; Z = 2; 4232 data, R1 = 0.0685] reveals a compound with oxygen anions forming a closest‐packed arrangement. Within this packing In3+ cations occupy octahedral interstices, forming layers of edge sharing octahedra. In between these layers are regions with composition [Zn4GaO5]+ forming a wurtzite type of structure. Inversions of the ZnO4 tetrahedra occurs (i) at the InO6 octahedral layer and (ii) halfway in the wurtzite type region, where the inversion boundary is built by Ga3+ in trigonal bipyramidal coordination with a long Ga–Oapical distance of 2.19(1) Å. The site occupation of Zn2+ and Ga3+, respectively, was confirmed by bond valence sum calculations. The compounds described here have the same structural charactistics as other known members with general formula ARO3(ZnO)m with m = integer. 相似文献
733.
734.
735.
以三乙二醇为表面配体, 利用沉淀法制备了β-Ga2O3∶Cr3+近红外(NIR)长余辉纳米颗粒. 考察了反应条件对β-Ga2O3∶Cr3+的发光性能和晶体结构的影响, 并初步探讨了其NIR余辉发光机理. 结果表明, 当溶液的pH值为7, 煅烧温度为700 ℃时, 可获得高纯度的β-Ga2O3∶Cr3+纳米颗粒, 其平均粒径为30 nm, 最大余辉发射波长可调控为750 nm, NIR余辉发光时间长于384 h. 本方法得到的β-Ga2O3∶Cr3+长余辉纳米颗粒不仅尺寸小, 而且NIR余辉时间长, 发射波长可调控, 在低背景噪音的深组织活体成像中具有潜在的应用前景. 相似文献
736.
Reactions of 1,2-catechol with tBu3M (M = Ga, In) have been studied. Trinuclear compounds [tBu5M3(OC6H4O)2] [M = Ga (1), M = In (2)] were synthesised in the reaction of 2 equiv. of C6H4(OH)2 with 3 equiv. of tBu3M in refluxing solvents. At room temperature the reaction of 1,2-catechol with tBu3In in Et2O leads to the formation of a binuclear complex [tBu4In2(OC6H4OH)2 · 2Et2O] (3) possessing a four-membered In2O2 core and two unreacted hydroxyl groups. The same reaction carried out in a non-coordinating solvent (CH2Cl2) results in formation a compound [tBu3In2(OC6H4O)(OC6H4OH)] (4), which undergoes a reaction with tBu3In to yield the product 2. Moreover two intermediate isomeric products 5 and 6 of formula [tBu3Ga2(OC6H4O)(OC6H4OH)] were isolated from the post-reaction mixture of 1,2-catechol with tBu3Ga. The compound 6 possessing a different coordination of gallium atoms than 5 is a result of the intramolecular rearrangement of the compound 5 to decrease the steric repultion between ligands. Compounds 3 and 6 were structurally characterised. According to the structure of intermediate products 3-6 a reaction pathway of 1,2-catechols with group 13 metal trialkyls was proposed. 相似文献
737.
用电弧熔炼法合成了系列化合物REGaSi,采用粉末X射线衍射方法测定了化合物SmGaSi的晶体结构,获得其晶体学及结构修正参数为;四方晶系,LaPtSi类型,(109)I41md,Mr=250.0,a=0.4134(3)nm,c=1.422(2)nm,V=0.2430(5)nm^3,Z=4,Dx=6.464g.cm^-3,F(000)=428,T=296K。 相似文献
738.
Synthesis and X‐Ray Structure Determination of iso ‐Butylimido Galliummethyl, [CH3Ga–NCH2CH(CH3)2]6 The thermal decomposition of [Me2Ga–N(iBu)SnMe3]2 (prepared by the reaction of [Me2SnNiBu]3 with GaMe3 in a 1:3 molar ratio) in an evacuated, sealed tube at 160°C forms [MeGaNiBu]6 in high yield and SnMe4. Mass, 1H and 13C NMR as well as some IR and Raman spectroscopic data are given and the crystal structure of this cage molecule with a hexagonal prismatic Ga6N6 skeleton has been determined. 相似文献
739.
Reactions of a Ga/P‐Based Frustrated Lewis Pair with HX (X = F – I), Heterocumulenes R–NCY (Y = O,S) and Chalcogens–Adduct Formation and Surprising Stability towards Protolysis 下载免费PDF全文
Treatment of the geminal Ga/P‐based frustrated Lewis pair (FLP) Mes2P–C(GatBu2)=C(H)–Ph ( 1 ) with HX (X = F, Cl, Br, I) afforded the corresponding adducts 2 with the protons bound to the P and the halide anions coordinated to the Ga atoms. Short intramolecular contacts may indicate P–H ··· X hydrogen bonding interactions. The Br and I compounds ( 2c , 2d ) were accessible in moderate yields even when aqueous solutions of the acids were employed. These unexpected reactions confirm the surprising stability of FLP 1 towards protolysis. Heterocumulenes R–N=C=Y (Y = O, S) and 1 yielded adducts with two different structural motifs. The N=C=Y groups were coordinated to the FLP either via the C=Y (Y = S; Ph–N=C=O) or the C=N bonds (Ph–N=C=O, Et–N=C=O). For phenyl isocyanate the C=O bonded isomer was observed in the solid state, while both isomeric forms were detected in solution. Steric shielding and the hardness of the atoms may influence the formation of the respective isomer. Cleavage of the C=S bonds of isothiocyanates was observed for the first time and afforded a sulfur adduct 9a , in which an S atom (electron sextet) was bound to the lone pair of electrons at phosphorus and to the Lewis acidic Ga atom. Four‐membered PCGaY heterocycles resulted, which were also synthesized in high yields by the direct reaction of 1 with propylene sulfide or selenium. 相似文献
740.