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11.
The reactions of the unsymmetrical, coordinatively unsaturated dirhenium(II) complexes [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)]Y (XylNC = 2,6-dimethylphenyl isocyanide; Y = O(3)SCF(3) (3a), PF(6) (3b)) with XylNC afford at least three isomeric forms of the complex cation [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)](+). Two forms have very similar bis(&mgr;-halo)-bridged edge-sharing bioctahedral structures of the type [(CO)BrRe(&mgr;-Br)(2)(&mgr;-dppm)(2)Re(CNXyl)(2)]Y (Y = O(3)SCF(3) (4a/4a'), PF(6) (4b/4b')), while the third is an open bioctahedron [(XylNC)(2)BrRe(&mgr;-dppm)(2)ReBr(2)(CO)]Y (Y = O(3)SCF(3) (5a), PF(6) (5b)). While the analogous chloro complex cation [Re(2)Cl(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)](+) was previously shown to exist in three isomeric forms, only one of these has been found to be structurally similar to the bromo complexes (i.e. the isomer analogous to 5a and 5b). The reaction of 3a with CO gives the salt [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(2)(CNXyl)]O(3)SCF(3) (7), in which the edge-sharing bioctahedral cation [(XylNC)BrRe(&mgr;-Br)(&mgr;-CO)(&mgr;-dppm)(2)ReBr(CO)](+) has an all-cis arrangement of pi-acceptor ligands. The Re-Re distances in the structures of 4b', 5a, and 7 are 3.0456(8), 2.3792(7), and 2.5853(13) ?, respectively, and accord with formal Re-Re bond orders of 1, 3, and 2, respectively. Crystal data for [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)](PF(6))(0.78)(ReO(4))(0.22).CH(2)Cl(2) (4b') at 295 K: monoclinic space group P2(1)/n (No. 14) with a = 19.845(4) ?, b = 16.945(5) ?, c = 21.759(3) ?, beta = 105.856(13) degrees, V = 7038(5) ?(3), and Z = 4. The structure was refined to R = 0.060 (R(w) = 0.145) for 14 245 data (F(o)(2) > 2sigma(F(o)(2))). Crystal data for [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(CNXyl)(2)]O(3)SCF(3).C(6)H(6) (5a) at 173 K: monoclinic space group P2(1)/n (No. 14) with a = 14.785(3) ?, b = 15.289(4) ?, c = 32.067(5) ?, beta = 100.87(2) degrees, V=7118(5) ?(3), and Z = 4. The structure was refined to R = 0.046 (R(w) = 0.055) for 6962 data (I > 3.0sigma(I)). Crystal data for [Re(2)Br(3)(&mgr;-dppm)(2)(CO)(2)(CNXyl)]O(3)SCF(3).Me(2)CHC(O)Me (7) at 295 K: monoclinic space group P2(1)/n (No. 14) with a = 14.951(2) ?, b = 12.4180(19) ?, c = 40.600(5) ?, beta = 89.993(11) degrees, V = 7537(3) ?(3), and Z = 4. The structure was refined to R = 0.074 (R(w) = 0.088) for 6595 data (I > 3.0sigma(I)). 相似文献
12.
The reaction of Fe2(CO)6(μ-S2),1 withbis(dibenzylideneacetone)-palladium, Pd(dba)2, in the presence of 2,2′-bipyridine yielded the new compound Fe2(CO)6(μ 3-S)2Pd(bipy),2 in good yield (66%). Compound2 was characterized by IR,1H NMR and single-crystal X-ray diffraction analyses. Compound2 contains a Pd(bipy) group that has been inserted into the S-S bond of1. Crystal data for2: space group P21/n,a=10.019(2) Å,b=25.414(5) Å,c=7.714(2) Å,β=90.26(2)°,Z=4, 1436 reflections,R=0.023. 相似文献
13.
From the reaction of [Ru5(C)(CO)14]2– with Pt(COD)Cl2, COD=1, 5 cyclooctadiene, the new platinum-ruthenium carbido cluster complex PtRu5 (C)(CO)14(COD),1, was obtained in 41% yield. When1 was allowed to react with carbon monoxide (25°C/1 atm), the new complex PtRu5(C)(CO)16,2, was obtained almost quantitatively (97% yield). Compound2 was characterized by IR and single-crystal X-ray diffraction analysis. The six metal atoms are arranged in the form of an octahedron with the carbide ligand located in the center. Compound1 is believed to have a similar structure to2 except for a COD ligand coordinated to the platinum atom. When activated by treatment with Me3NO, compound2 reacts with Pt(COD)2 at 25°C to yield two higher nuclearity cluster complexes, Pt2Ru5C(CO)13(COD)2.3, and Pt3Ru5C(CO)14(COD)2,4. The structure of3 is similar to that of1, but contains a Pt(COD) grouping capping one Ru3 triangle of the PtRu5 octahedron. The structure of4 consists of a PtRu5 octahedron with two Pt(COD) capping groups, one on an Ru3 triangle and the other on a PtRu2 triangle of the octahedron. Crystal data: for2, space group=P21/n,a=9.341 (2) Å,b=14.957 (3) Å,c=36.80 (1) Å, =90.38 (2) °,Z=8, 4034 reflections,R=0.030, for3, space group=P21/c,a=14.998 (3) Å,b=10.288 (3) Å,c=26.581 (7) Å, =102.75 (2) °,Z=4, 2917 reflections,R=0.028. for4, space group=P21/n,a=13.412 (4) Å,b=16.252 (4) Å,c=20.107 (4) Å, =106.13 (2) °,Z=4, 2745 reflections,R=0.032. 相似文献
14.
Wengan Wang Guisheng Zou Na Chen Qiang Jia Bin Feng Hongqiang Zhang Zhongyang Deng Lei Liu 《Particle & Particle Systems Characterization》2023,40(7):2200195
Low-temperature bonding (≤300 o C) using Ag nanoparticles (Ag NPs) is considered to be the new generation of bonding technology in power electronics. The oxygen-accelerated sintering has been observed by many researchers which is attributed to the decomposition of organics covered on Ag NPs. In this work, organic-free Ag NPs are fabricated to eliminate the influence of organics, and it is found that the accelerated bonding process by oxygen is strongly correlated to the self-confined amorphous Ag-O compound shell on the surface of Ag NPs. In experiments, the sintering process is apparently accelerated by the elevating oxygen content, and the amorphous shell is observed after sintering, which do not grow thicker even in pure oxygen ambient for a long time while performing active chemical evolutions. In simulations, the results match well with the experiments and indicate that the amorphous shell performed the dynamic oxidation and decomposition process. This dynamic equilibrium is caused by the instability of silver oxides, which would enable the amorphous shell to activate the mobility of the surface mass flow and promote the surface diffusion. The shear strength of SiC chip increased by 354% when bonding in pure oxygen, targeting a broad variety of applications in electronic packaging. 相似文献
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16.
Richard D. Adams Gong Chen Linfeng Chen Michael P. Pompeo Wengan Wu 《Journal of Cluster Science》1992,3(1):103-108
Agostic interactions of CH bonds with metal atoms are currently of great interest. UV irradiation of Mn2(CO)8 (PMe2Ph)2 in the presence of the HCCOEt yielded the new compound Mn2(CO)6(PMe2Ph)2 [-C(OEt)=C(H)C=C(H)C=O(OEt)],1 that contains a strong agostic interaction of an olefinic CH bond to one of the managanese atoms, Mn...C=2.349(5), Mn...H=2.01(4). This interaction can be removed (reversibly) by CO addition (25°C/1000 psi) to1 to yield the new complex Mn2(CO)7(PMe2Ph)2[-C(OEt)=C(H)C=C(H)C=O(OEt)],2. 相似文献
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18.
From the reaction of Ru(CO)5 and Pt(COD)2, COD = 1, 5-cyclooctadiene, the new platinum-ruthenium heteronuclear cluster complex Pt2Ru4(CO)18,1, was obtained in 60% yield.1 has a folded ladder-like structure with alternating pairs of ruthenium atoms and platinum atoms. The cluster of1 can be split to yield the known compound PtRu2(CO)8(2-dppe),2, (54% yield) by reaction with 1, 2-bis(diphenylphosphino)ethane, dppe, at 25°C. When1 was treated with excess dppe at 40°C, thebis-diphos compound3, PtRu2(CO)6(-2-dppe)2 was obtained (39% yield). Under the similar reaction conditions,2 was converted to3 in 44% yield. All these complexes were characterized by single crystal X-ray diffraction analyses. Compounds2 and3 both contain a triangular cluster of one platinum and two ruthenium atoms, but in2 the bidentate ligand, dppe, chelates the platinum atom and in3 the two dppe ligands bridge the two Pt-Ru metal-metal bonds. Crystal data for1: space group C2/c,a=12.542(2)Å,b=15.350(4)Å,c=15.252(3)Å, =105.32(2)°,Z=4, 2192 reflections,R=0.025. For2: space group P21/c,a=14.351(2)Å,b=13.486(3)Å,c=19.218(3)Å, =108.48(1)°,Z=4, 3029 reflections,R=0.027. For3: space group P21/c,a=18.836(6)Å,b=15.559(5)Å,c=23.259(7)Å, =111.26(2)°,Z=4, 4204 reflections,R=0.038. 相似文献