OXO-CENTERED HETEROTRINUCLEAR TRANSITION METAL CARBOXYLATE COMPLEXES 3, SYNTHESES AND X-RAY STRUCTURAL CHARACTERISTICS OF COMPOUNDS Fe_2MO(O_2CCCl_3)_6(THF)_3 (1,M = Mn;2,M=Co;3, M = Ni;THF=TETRAHYDROFURAN)

<正> The title compounds have been synthesized and characterized by x-ray analysis. They are isomorphous, belonging to trigonal space group R3m,with crystallo-graphic parameters; (1)α =b =c= 13. 713(5) A ;α= β=γ=83. 66(3)°;V = 2535A3;Z = 2;DC=1. 80gcm-3;F(000) = 1358;M= 1373. 23;(2)α= b = c=13. 687(2) A;α = β = γ = 84. 27(1)°/;V = 2528. 0A3;Z = 2; Dc = 1. 81gcm-3; F (000)= 1362; M = 1377. 23;(3)α = b=c=13. 671(6) A ;α = β = γ=84. 12(3)°;V=2518A3;Z=2;DC = 1. 82 gcm-3;F(000)= 1364;Mr= 1376. 99.The structure of comp ound 2 has been determined with the final R= 0. 061 for 845 reflections with I≥3σ(Ⅰ).The three metal atoms are crystallographically equivalent because of the arbitrariness of orientation of the molecules,and in the sense of crystallography the molecule Fc2CoO(O2CCCl3)6(THF)3 is of C3vsymmetry with centered oxygen atom on the 3-fold axis. The atoms M,C(1~4),C1(1) and O(1) lie on the mirror. Three CC13 groups on one side the Fe2CoO plane and three terminal THF ligands are dynamically     

Syntheses of (C_5H_9C_5H_4)_2LnCl(THF)_n (Ln=Nd, Sm, Er, Yb) and crystal structure of [(C_5H_9C_5H_4)_2-LnCl(THF)_n]_2(Ln=Sm, n=1; Ln=Er, n=0)

Reactions of lanthanoid trichlorides with sodium cyclopentylcyclopentadienyl in THFafford bis(cyclopentylcyclopentadienyl) lanthanoid chloride complexes (C_5H_9C_5H_4)_2LnCl(THF)_n (Ln=Nd, Sm, n=1; Ln= Er, Yb, n= 0). The compound [CP'_2SmCl(THF)]_2 (2) (Cp' =cyclopentylcy-clopentadienyl) crystallizes from mixed solvent of hexane and THF in monoclinic space group P_2_1/cwith a = 11.583 (3), b = 23.019(6), c = 8.227 (2), β= 90.26 (2)°, V= 2194 (1)~3, D_c= 1.59 g/cm~3.μ= 28.6 cm~(-1), F(000) = 1060, Z= 2 (dimers). Its crystal molecule is a dimer with a crystallographicsymmetry center. The central metal atom Sm is coordinated to two Cp' rings, two bridging chlorineatoms and one THF forming a distorted trigonal bipyramid. The crystal of [Cp'_2ErCl]_2 (3) belongs tothe triclinic space group P with a = 11.264 (2), b= 13.296(5), c = 14.296(6), a = 96.99 (3), β=112.47(2), γ= 102.78(2)°, V= 1865(1)~3, D_c= 1.67 g /cm~3, μ= 48.0 cm~(-1), F(000) = 924, Z = 2 (dimers).The molecule is a dimer consisting of two Cp'_2 ErCl species bridged by two Cl atoms. The centralmetal atom Er is coordinated to two Cp' rings and two bridging chlorine atoms forming a pseudo-tetrahedron. All these complexes are soluble in THF, DME, Et_2O, toluene and hexane.     

(MN)nHm(M=Ga,In; n=1-4; m=1, 2)团簇的结构与稳定性

采用密度泛函理论(DFT)的B3LYP方法, 在6-31G**和Lanl2dz水平上分别对(MN)nHm(M=Ga, In; n=1-4; m=1, 2)进行了优化和振动频率计算. 得到了上述团簇的最稳定构型、H原子的结合能以及它们的能隙. 结果表明, (MN)nH(M=Ga, In; n=1-4)的基态构型均为双重态, (MN)nH2(M=Ga, In; n=1-4)的基态构型均为单重态; 当氢的个数为1时, 加在N原子上比加在M(M=Ga, In)原子上稳定, 如有N3单元, 那么加在N3单元两侧的构型是相同的, 且它是最稳定的; 当氢的个数为2时, 除n=1外, 分别加在两个N原子上的构型是最稳定的, 如有N3单元, 那么分别加在N3单元分离最远的两个N原子的构型是最稳定的. GaNH、(GaN)3H 和InNH的结合能和能隙都很大, 说明这些团簇都有很高的稳定性.     

Syntheses and Crystal Structures of Two Supramolecular Architectures:(H_2tfbdc)·(tfbdc)·(Hbipy)_2 and (tfbdc)·(H_2pz)(tfbdc=Tetrafluoroterephthalate,bipy=4,4'-Bipyridine,pz=Pyrazine)

Two new supramolecular compounds,2C 10 H 9 N 2 + ·C 8 HF 4 O 4 2-·C 8 H 2 F 4 O 4 /(H 2 tfbdc)· (tfbdc)·(Hbipy) 2 (1) and C 4 H 6 N 2 2+ ·C 8 HF 4 O 4 2-/(tfbdc)·(H 2 pz) (2),were synthesized and characterized by elemental analysis,IR spectra,and single-crystal X-ray diffraction.Compound 1 crystallizes in the triclinic system,space group P1,with a=8.3453(12),b=10.1798(15),c=10.6626(16),α=87.591(2),β=74.047(2),γ=69.006(2)°,V=834.53(12) 3,D c=1.614 g/cm 3,F(000)=400,u=1.45 cm-1,Z=2,the final R=0.0353 and wR=0.1005 for 5882 observed reflections with I > 2σ(I);and compound 2 crystallizes in the monoclinic system,space group P2 1 /c,with a=10.471(4),b=5.4419(19),c=12.249(4),β=114.909(6)°,V=633(4)3,D c=1.669 g/cm 3,F(000)=320,u=1.63 cm-1,Z=2,the final R=0.0794 and wR=0.2923 for 3213 observed reflections with I > 2σ(I).Both compounds 1 and 2 crystallize as charge-transfer organic salts with the dianionic or neutral acid components lying at the inversion centers.Hbipy + cations and anionic acid in compound 1 are linked to form a chain by means of C-H···O hydrogen bonds.Adjacent chains are further extended into a two-dimensional layer network via N-H···O and O-H···N hydrogen bonds.In compound 2,the acid and base subunits are arranged alternately to generate a linear tape motif via N-H O hydrogen bonds;these tapes are further combined into a three-dimensional array with CdSO 4 topology via C-H O intermolecular hydrogen bonds.     

Synthesis and Structure of 1.5Zn(phen)_3·L·3NO_3 Supramolecule(phen=o-Phenanthroline,L=4-Aminoacetophenone Thiosemicarbazone)

A supramolecular framework,1.5Zn(phen)3·L·3NO3(C63H48Zn1.5N16O9S),has been synthesized.The ligand L was synthesized by the condensation of p-aminoacetophenone with thiosemicarbazide.The crystal belongs to the monoclinic system,space group C2/c,with a = 31.005(2),b = 15.114(2),c = 24.887(3) ,β = 94.260(2)o,Z = 8,V = 11630(2) 3,Dc = 1.489 g/cm3,Mr = 1303.29,λ(MoKα) = 0.71069 ,μ = 0.735 mm-1,F(000) = 5368,Rint = 0.0699,R = 0.0505 and wR = 0.0707.Two independent Zn atoms are both coordinated by six N atoms from three phen ligands.π-π and C-H···π interactions among the L ligands and Zn(phen)3 cations,π-π and C-H···π interactions among the Zn(phen)3 cations and N-H···O hydrogen bonds among the L ligands and nitrate anions connect the whole structure into a 3-D supramolecular framework.     

STRUCTURE OF MOLECULAR COMPOUND CRYSTAL A_2B(A =1, 6, 7, 8,-TETRA-PHENYL (3, 4-BENZO)BICYCLO[4, 2, 0]OCTA-7-ENE, B=CIS, CIS-1,2,3,4,-TETRAPHENYLBUTADIENE)

<正> C100H78, (A: C36H28, B: C28H22) Mr = 1279. 74, monoclinic, P21/a, a=17. 282(3), b=10. 669(4), c= 19, 927(3) A , β =102. 99(1)°,V = 3580. 1(2) A3, Z=2, μ(MoKα) = 0. 623cm-1, F(000) = 1356, Dc=1. 187g/cm3, room temperature. The final R=0. 084, Rw = 0. 086 for 1255 independent observed reflections (I≥3σ(I)). Owing to the existence of 1,6,7, 8-Tetraphenyl (3,4-benzo)-bicyclo[4, 2, 0]octa-7-ene(A) , cis, cts-1, 2, 3, 4-Tetraphenylbutadiene (B) in A2B can take the different conformation from the one in the pure B crystal. The reason of the formation of this molecular compound crystal is put forward.     

三元体系Ln(ClO4)3-4-ClCH2COAp-H2O(30℃)的相平衡研究(Ln=La,Sm,Er)

我们测定了三元体系 Ln(ClO_4)_3—4-ClCH_2COA_p—H_2O(Ln=La,Sm,Er)存30℃时的溶度及饱和溶液的折光指数,绘制了相应的溶度图和饱和溶液的折光指数曲线图.体系的溶度曲线和折光指数曲线均由四支组成,分别与4-ClCH_2COA_p、Ln(4-ClCH_2COAp)_3(ClO_4)_3·nH_2O(Ln=La,n=7;Sm,8;Er,4)、Ln(4-ClCH_2COAp)_2(ClO_4)_3·nH_2O(Ln=La,n=7;Sm,6;Er,4)和 Ln(ClO_4)_3·nH_2O(Ln=La,n=8;Sm,9;Er,6)相对应,两类配合物均为固液异组成化合物.     

金属串配合物(n,m)[Cr3(PhPyF)4Cl2](n=2, 3, 4; m=2, 1, 0)的配位结构及其与电场的关系

应用密度泛函理论BP86 方法研究具有分子导线潜在应用的金属串配合物(n, m)[Cr₃(PhPyF)₄Cl₂](HPhPyF=N, N'-苯基吡啶基甲脒; n=2, 3, 4; m=2, 1, 0)的配位结构及其受电场作用的影响, n、m分别表示PhPyF-的苯环在左侧和在右侧的配体个数. 结果表明: (1) 零电场下, 四个PhPyF-的(2, 2)、(3, 1)和(4, 0)三种配位方式能量差别很小, 为竞争态, (2, 2)最稳定. (4, 0)结构中两端轴向配体Cl 均可与Cr 配位, 且Cl₄―Cr1 键比Cl5―Cr3键更强, 若作为分子器件可与电极结合, 这与(4, 0)[CuCuM(npa)₄Cl][PF₆](M=Pd, Pt; Hnpa=2-萘啶苯胺)靠近苯环一端的轴向配体无法与M配位不同. (2) 在(2, 2)、(3, 1)和(4, 0)中, Cr₃⁶⁺链均具有三中心三电子离域σ键, 但离域性逐渐减弱. 随四个PhPyF-配位方式趋于一致, 分子极性逐渐增大, 由Cl₄指向Cl5(Z)方向, Cr1的α自旋密度增大, Cr2 的β和Cr3 的α自旋密度减小. (3) 分子的几何结构和电子结构在电场下发生规律性变化, 在-Z方向电场作用下, (3, 1)、(4, 0)电子移动方向与极性方向相同, 使分子的键长、自旋密度、电荷和能隙变化显著性均大于Z方向电场, 且极性越大变化越显著, 有利于提高分子导电性.     

碳酸酐酶的化学模拟——含三(取代吡唑)硼氢根的金属配合物[η3-HB(3-Ar-5-Mepz)3]MX(M=Ni,Cu,Zn,Cd;Ar=2''''-thie,Ph;x=Cl,NO3)的合成和表征

合成了标题所示的一系列新的含三(取代吡唑)硼氢根的金属配合物,均通过元素分析、IR、1H NMR进行表征.配合物[η3-HB(3-(2'-thie)-5-Mepz)3]Zn(NO3)·1/2THF(2c)的晶体结构测定表明,硝酸根是以不对称双齿方式与Zn原子配位(Zn-O(2)键长为0.1966(4)nm,Zn-O(3)键长为0.2463(4)nm);而在镉的类似物{[η3-HB(3-Ph-5-Mepz)3]Cd(NO3)(THF)}(2e)中,NO-3则以双齿方式与Cd原子配位[Cd-O键长为0.2334(3)和0.2356(3)nm].NO-3随金属不同取不同方式配位的现象,为解释锌、镉碳酸酐酶的不同活性(与酶活性中心配位的HCO-3是NO-3的等电子体)提供了进一步的依据.配合物2c和2e均为三斜晶系,P-1空间群,Z=2.2c晶胞参数:a=1.16250(10),b=1.2422(2),c=1.32590(10)nm;α=71.410(10)°,β=73.090(10)°,γ=65.660(10)°;R=0.0755.2e品胞参数:a=1.13030(10),b=1.2099(2),c=1.2607(2)nm;α=102.050(10)°,β=91.780(10)°,γ=93.620(10)°;R=0.0302.     

三元体系Ln(ClO4)3-4-ClCH2COAp-H2O(30℃)的相平衡研究(Ln=La,Sm,Er)

我们测定了三元体系Ln(ClO4)3-4-ClCh2COAp-H2O(Ln=La,Er)在30℃时的溶度及饱和溶液的折光指数,绘制相应的溶度图和饱和溶液的折光指数曲线图。体系的溶度曲线和折光指数曲线均由四支组成,分别与4-ClCh2COAp、Ln(4-ClCh2COAp)3·nH2O(Ln=La,n=7;Sm,8;Er,4)、Ln(4-ClCH2COAp)2(ClO4)3·nH2O(Ln-La,n=7;Sr,6;Er,4)和Ln(ClO4)3·nH2O(Ln=La,n=8;Sm,9;Er,6)相对应,两类配合物均为固液异组成化合物。     

Bis(dimethylmetall(III)glyoximato)metallate(II) (metall(III) = Al,Ga, In,metall(II) = Ni,Pd, Pt,Cu)

When the trimethyl derivatives of aluminium, gallium and indium react with glyoximato metallates, (R₂C₂N₂(O)OH)₂Met^II (R = H, CH₃; Met^II = Ni, Pd, Pt, Cu), in a $\text{2}\text{1}$ molar ratio, 2 mol of methane are evolved and monomeric bis(dimethylmetal(III)glyoximato)metallates(II) (metal(III) = Al, Ga, In) are formed in high yields. The vibrational and NMR spectra of the new complexes were measured and were partly resolved. The X-ray structure determinations of two of these compounds show non-planar structures of approximate C_2h and C₂ symmetry, respectively, with weak metal(III)?metal(II) π-interactions.     

Phosphasila-, phosphagerma-, and phosphaarsaallenes --P=C=E (E = Si,Ge, As) and arsa- and diarsaallenes --As=C=E" (E" = C,As)

The paper reviews the contribution from our group to the studies of heteroallenes. The transient 1,3-phosphasilaallene ArP=C=Si(Ph)Tip (Ar = 2,4,6-tri-tert-butylphenyl, Tip = 2,4,6-triisopropylphenyl) and 1,3-phosphagermaallene ArP=C=GeMes₂ (Mes = 2,4,6-trimethylphenyl) were characterized below –40 °C by NMR spectroscopy and chemical trapping. These compounds dimerize above –40 °C through two routes. With increased steric hindrance on germanium, the phosphagermaallene ArP=C=Ge(Bu^t)Tip was stabilized as monomer at room temperature. 3-Chloro-2-lithio-1,3-phosphasilapropene ArP=C(Li)Si(Cl)CMeR₂ (CMeR₂ = 9-methylfluorenyl) behaves, at least in some cases, as a synthetic equivalent of the functionalizable allene ArP=C=Si(Cl)CMeR₂. Arsaallene ArAs=C=CR₂, phosphaarsaallenes ArP=C=AsAr and ArP=C=AsDmt (Dmt = 2,6-dimesityl-4-methylphenyl), and diarsaallene ArAs=C=AsAr exhibit a higher thermal, air, and moisture stability than the above phosphasilaallenes and phosphagermaallenes. The physicochemical data for the arsaallenes and diarsaallenes, particularly, their X-ray structural parameters, display a bonding system close to allenes. On going down the Periodic table, the stabilization becomes more difficult. For this reason, tin allenic derivatives are very rare and antimony allenic compounds have not yet been isolated.     

Synthesis, structure, and multi-NMR studies of (Me4N)[A(M(SC(O)Ph)3)2] (A = Na, M = Hg; A = K, M = Cd or Hg)

The compounds (Me4N)[A(M(SC(O)Ph)3)2] (A = K, M = Cd (2); A = Na, M = Hg (3); and A = K, M = Hg (4)) were synthesized by reacting the appropriate metal chloride with A+PhC(O)S- and Me4NCl in the ratios 1:3:1 and 2:6:1. The structures of these compounds were determined by single-crystal X-ray diffraction methods. All the compounds are isomorphous, isostructural, and crystallized in the space group P1 with Z = 1. Single-crystal data for 2: a = 106670(2) A, b = 111522(2) A, c = 119294(2) A, alpha = 71782(1) degrees, beta = 85208(1) degrees, gamma = 69418(1) degrees, V = 126140(4) A3, Dcalc = 1528 g cm-3. Single-crystal data for 3: a = 10840(2) A, b = 10946(4) A, c = 12006(3) A, alpha = 7218(2) degrees, beta = 8675(2) degrees, gamma = 6743(2) degrees, V = 12493(6) A3, Dcalc = 1756 g cm-3. Single-crystal data for 4: a = 104780(1) A, b = 112563(2) A, c = 119827(2) A, alpha = 71574(1) degrees, beta = 85084(1) degrees, gamma = 70705(1) degrees, V = 126523(3) A3, Dcalc = 1755 g cm-3. In the [A(M(SC(O)Ph)3)2]- anions, each M(II) atom is bonded to three thiobenzoate ligands through sulfur atoms, giving a trigonal planar MS3 geometry. The carbonyl oxygen atoms from the two [M(SC(O)Ph)3]- anions are bonded to the alkali metal atom, providing an octahedral environment. Solution metal NMR studies showed the concentration-dependent dissociation of the alkali metal ions in the trinuclear anions.     

Synthesis and characterization of (smif)2M(n) (n = 0, M = V, Cr, Mn, Fe, Co, Ni, Ru; n = +1, M = Cr, Mn, Co, Rh, Ir; smif =1,3-di-(2-pyridyl)-2-azaallyl)

A series of Werner complexes featuring the tridentate ligand smif, that is, 1,3-di-(2-pyridyl)-2-azaallyl, have been prepared. Syntheses of (smif)(2)M (1-M; M = Cr, Fe) were accomplished via treatment of M(NSiMe(3))(2)(THF)(n) (M = Cr, n = 2; Fe, n = 1) with 2 equiv of (smif)H (1,3-di-(2-pyridyl)-2-azapropene); ortho-methylated ((o)Mesmif)(2)Fe (2-Fe) and ((o)Me(2)smif)(2)Fe (3-Fe) were similarly prepared. Metatheses of MX(2) variants with 2 equiv of Li(smif) or Na(smif) generated 1-M (M = Cr, Mn, Fe, Co, Ni, Zn, Ru). Metathesis of VCl(3)(THF)(3) with 2 Li(smif) with a reducing equiv of Na/Hg present afforded 1-V, while 2 Na(smif) and IrCl(3)(THF)(3) in the presence of NaBPh(4) gave [(smif)(2)Ir]BPh(4) (1(+)-Ir). Electrochemical experiments led to the oxidation of 1-M (M = Cr, Mn, Co) by AgOTf to produce [(smif)(2)M]OTf (1(+)-M), and treatment of Rh(2)(O(2)CCF(3))(4) with 4 equiv Na(smif) and 2 AgOTf gave 1(+)-Rh. Characterizations by NMR, EPR, and UV-vis spectroscopies, SQUID magnetometry, X-ray crystallography, and DFT calculations are presented. Intraligand (IL) transitions derived from promotion of electrons from the unique CNC(nb) (nonbonding) orbitals of the smif backbone to ligand π*-type orbitals are intense (ε ≈ 10,000-60,000 M(-1)cm(-1)), dominate the UV-visible spectra, and give crystals a metallic-looking appearance. High energy K-edge spectroscopy was used to show that the smif in 1-Cr is redox noninnocent, and its electron configuration is best described as (smif(-))(smif(2-))Cr(III); an unusual S = 1 EPR spectrum (X-band) was obtained for 1-Cr.     

Ligand dependence of metal-metal bonding in the d(3)d(3) dimers M(2)X(9)(n-) (M(III) = Cr, Mo, W; M(IV) = Mn, Tc, Re; X = F, Cl, Br, I)

The ligand dependence of metal-metal bonding in the d(3)d(3) face-shared M(2)X(9)(n-) (M(III) = Cr, Mo, W; M(IV) = Mn, Tc, Re; X = F, Cl, Br, I) dimers has been investigated using density functional theory. In general, significant differences in metal-metal bonding are observed between the fluoride and chloride complexes involving the same metal ion, whereas less dramatic changes occur between the bromide and iodide complexes and minimal differences between the chloride and bromide complexes. For M = Mo, Tc, and Re, change in the halide from F to I results in weaker metal-metal bonding corresponding to a shift from either the triple metal-metal bonded to single bonded case or from the latter to a nonbonded structure. A fragment analysis performed on M(2)X(9)(3-) (M = Mo, W) allowed determination of the metal-metal and metal-bridge contributions to the total bonding energy in the dimer. As the halide changes from F to I, there is a systematic reduction in the total interaction energy of the fragments which can be traced to a progressive destabilization of the metal-bridge interaction because of weaker M-X(bridge) bonding as fluoride is replaced by its heavier congeners. In contrast, the metal-metal interaction remains essentially constant with change in the halide.     

Dinuclear gold(I) dithiophosphonate complexes: synthesis,luminescent properties,and X-ray crystal structures of [AuS(2)PR(OR')](2) (R = Ph,R' = C(5)H(9); R = 4-C(6)H(4)OMe,R' = (1S,5R,2S)-(--)-menthyl; R = Fc,R' = (CH(2))(2)O(CH(2))(2)OMe)

2,4-Diaryl- and 2,4-diferrocenyl-1,3-dithiadiphosphetane disulfide dimers (RP(S)S)(2) (R = Ph (1a), 4-C(6)H(4)OMe (1b), FeC(10)H(9) (Fc) (1c)) react with a variety of alcohols, silanols, and trialkylsilyl alcohols to form new dithiophosphonic acids in a facile manner. Their corresponding salts react with chlorogold(I) complexes in THF to produce dinuclear gold(I) dithiophosphonate complexes of the type [AuS(2)PR(OR')](2) in satisfactory yield. The asymmetrical nature of the ligands allows for the gold complexes to form two isomers (cis and trans) as verified by solution (1)H and (31)P[(1)H] NMR studies. The X-ray crystal structures of [AuS(2)PR(OR')](2) (R = Ph, R' = C(5)H(9) (2); R = 4-C(6)H(4)OMe, R' = (1S,5R,2S)-(-)-menthyl (3); R = Fc, R' = (CH(2))(2)O(CH(2))(2)OMe (4)) have been determined. In all cases only the trans isomer is obtained, consistent with solid state (31)P NMR data obtained for the bulk powder of 3. Crystallographic data for 2 (213 K): orthorhombic, Ibam, a = 12.434(5) A, b = 19.029(9) A, c = 11.760(4) A, V = 2782(2) A(3), Z = 4. Data for 3 (293 K): monoclinic, P2(1), a = 7.288(2) A, b = 12.676(3) A, c = 21.826(4) A, beta = 92.04(3) degrees, V = 2015.0(7) A(3), Z = 2. Data for 4 (213 K): monoclinic, P2(1)/n, a = 11.8564(7) A, b = 22.483(1) A, c = 27.840(2) A, beta = 91.121(1) degrees, V = 7419.8(8) A(3), Z = 8. Moreover, 1a-c react with [Au(2)(dppm)Cl(2)] to form new heterobridged trithiophosphonate complexes of the type [Au(2)(dppm)(S(2)P(S)R)] (R = Fc (12)). The luminescence properties of several structurally characterized complexes have been investigated. Each of the title compounds luminesces at 77 K. The results indicate that the nature of Au...Au interactions in the solid state has a profound influence on the optical properties of these complexes.     

[MPy4(NCO)2]-2Py clathrates (M = M(II) = Mn,Fe, Co,Ni, Cu,Zn, Cd; Py = pyridine)

The title compounds form an iso structural series and are isomorphic with other [MPy₄X₂]-2Py clathrates (XRD, KM4 diffractometer, cell parameters and space group Ccca from 17–80 reflections). In the clathrate [NiPy₄(NCO)₂]-2Py studied in detail (XRD, CAD-4 diffractom eter, λCuK_α, Ω/2θ scan mode, θ_max = 78‡, 990 strong reflections, 104 parameters, R = 0.053), the host molecule has 222 symmetry, and the twofold axes run along the coordination bonds. The transoctahedral environment of nickel consists of six nitrogen atoms of four pyridine and two isocyanate ligands. The coordination polyhedron is slightly distorted due to changes in the bond lengths. The molecule has a propeller conformation. The guest molecules lie in the cavities of the crystal structure in conformity with the van der Waals type of packing. The host complex [NiPy₄(NCO)₂] (XRD, CAD-4 diffractometer, 4615 strong reflections, 560 parameters, R-0.037) crystallizes in the triclinic crystal system (space group P1) with two independent asymmetric molecules in the unit cell. The molecular structure is analogous to that in the ciathrate phase, but the coordination angles are severely distorted; one of the molecules acquires a distorted propeller conformation, and the other, a centrosvmmetric conformation, which is less favorable. While being structurally identical, the [MPy₄(NCO)₂]-2Py clathrates differ heavily in the properties. The first four complexes dissociate to host complexes, and their thermal stability changes in the sequence Mn< Fe< Co< Ni; the Cu and Zn clathrates decompose in one step to dipyridine complexes with decomposition of host complexes. Decomposition of the Cd ciathrate follows one of these patterns depending on conditions. The results are compared with those for other known systems. Synthetic procedures are given. Translated fromZhurnal Strukturnoi Khimii, Vol. 40, No. 5, pp. 935–953, September–October, 1999.     

Silylchalcogenolates MESiR(t)Bu(2) (M = Na, Cu, Zn, Fe; E = S, Se, Te; R = tBu, Ph) and disilyldichalcogenides tBu2RSiE-ESiRtBu2 (E = S, Se, Te; R = tBu, Ph): synthesis, properties, and structures

The sodium silyl chalcogenolates NaESiR(t)Bu(2) (R = Ph, (t)Bu; E = S, Se, Te), accessible by the nucleophilic degradation of S, Se, or Te by the sodium silanides NaSiR(t)Bu(2) (R = Ph, (t)Bu), have been characterized by X-ray structure analysis. Protonolysis of the sodium silyl chalcogenolates yields the corresponding chalcogenols. The Cu and Zn chalcogenolates, [Cu(SSiPh(t)Bu(2))](4) and [ZnCl(SSi(t)Bu(3))(THF)](2), have been synthesized by metathesis reactions of CuCl with NaSSiPh(t)Bu(2) and of ZnCl(2) with NaSSi(t)Bu(3), respectively. The solid-state structures of the transition metal thiolates have been determined. The compounds (t)Bu(2)RSiE-ESiR(t)Bu(2) (R = Ph, (t)Bu; E = S, Se, Te) are accessible via air oxidation. With the exception of (t)Bu(3)SiS-SSi(t)Bu(3), these compounds were analyzed using X-ray crystallography and represent the first structurally characterized silylated heavy dichalcogenides. Oxidative addition of (t)Bu(3)SiTe-TeSi(t)Bu(3) to Fe(CO)(5) yields [Fe(TeSi(t)Bu(3))(CO)(3)](2), which has also been structurally characterized.     

Synthesis,Crystal Structures and Magnetic Properties of Ion-Pair Complexes with Hydrogen Bonding Network: Ln(DMA)n(H2O)m Cr(CN)6· xH2O(Ln = Sm,Gd: n = 4, m = 3, x = 2; Ln = Er: N = 3, m = 4, x = 0)

Three ion-pair Ln-Cr complexes [Sm(DMA)₄(H₂O)₃][Cr(CN)₆] · 2H₂O, [Gd(DMA)₃(H₂O)₄][Cr(CN)₆] · 2H₂O and [Er(DMA)₃(H₂O)₄][Cr(CN)₆] (DMA = dimethylacetamide) have been synthesized. X-ray structure analyses of the title complexes revealed that there is a hydrogen-bonding network through CN groups and H₂O molecules. Variable temperature magnetic susceptibilities indicate weak antiferromagnetic interactions between cation and anion pairs moderated through the hydrogen bonding network.