Structure of [C3H5O]+ ions produced from unimolecular decomposition of several [C4H8O]+˙ metastable ions

It is demonstrated by means of collisionally activated decomposition (CAD) that [C₃H₅O]⁺ originating from metastable [C₄H₈O]^+˙ ions are either acylium [C₂H₅CO]⁺ (a) or hydroxycarbenium [CH₂CHCHOH]⁺ (b). Butanone gives exclusively a but 2-methyl-2-propen-1-ol, 2-buten-1-ol, 3-buten-1-ol, butanal and 2-methylpropanal lead to ion b. Both structures a and b are produced from 3-buten-2-ol. These results are discussed in conjunction with experimental and calculated (MINDO/3) thermodynamic data.     

Syntheses of Stable α-Silyloxyepoxides and α-Chloroalkyl Silyl Ethers Derivatives of 3,10-Dioxa-5-azatricyclo[5.2.1.02,6]dec-4-enes

The Diels-Alder adduct (±)-5 of furan to 1-cyanovinyl acetate was converted to (1RS,2RS,6RS,7SR,8SR,10RS)-10-{[(tert-butyl)dimethylsilyl]-oxy}-4-ethoxy (1) and -4-phenyl-3,9,11-trioxa-5-azatetracyclo[5.3.1.0^2,6.0^8,10]-undec-4-ene (2). These compounds reacted with TiCl₄ to afford stable (1RS,2RS,6RS,7SR,8SR,9SR)-9-{[(tert-butyl)dimethylsilyl]oxy}-9-chloro-4-ethoxy-3,10-dioxa-5-azatricyclo[5.2.1.0^2,6]decan-8-ol (3) and (1RS,2RS,6RS,7SR,8SR,9SR)-9-{[(tert-butyl)dimethylsilyl]oxy}-9-chloro-4-phenyl-3,10-dioxa-5-azatricyclo[5.2.1.0^2,6]decan-8-ol (4), respectively.     

Three-dimensional (3-D) metal-organic frameworks with 3-pyridin-4-yl-benzoate defining new (3,6)-connected net topologies

Reactions of different metal salts with 3-pyridin-4-yl-benzoic acid (3,4-Hpybz) under ambient condition afford a series of 3-D metal-organic frameworks with two new types of (3,6)-connected net topologies. In the isomorphic complexes [M₂(μ-H₂O)(3,4-pybz)₄]_n (M^II=Mn^II for 1, Zn^II for 2, or Cd^II for 3), the octahedral metal nodes are extended by the 3-connected pybz tectons to constitute 3-D arrays with the Schläfli symbol of (3.4.5)(3².4⁴.5⁵.6².7²), whereas [Pb(3,4-pybz)₂]_n (4) shows a completely different 3-D (4².6)₂(4⁴.6².8⁹) framework, which represents a subnet of the (4,8)-connected fluorite lattice.     

Singlet-Oxygen Ene Reactions of (E)-4-Propyl[1,1,-2H3]oct-4-ene. Short Communication

Rose bengal-sensitized photooxygenation of 4-propyl-4-octene ( 1 ) in MeOH/Me₂CHOH 1:1 (v/v) and MeOH/H₂O 95:5 followed by reduction gave (E)-4-propyl-5-octen-4-ol ( 4 ), its (Z)-isomer 5 , (E)-5-propyl-5-octen-4-ol ( 6 ), and its (Z)-isomer 7 . Analogously, (E)-4-propyl[1,1,1-²H₃]oct-4-ene ( 2 ) gave (E)-4-propyl[1,1,1-²H₃]oct-5-en-4-ol ( 14 ), its (Z)-isomer 15 , (E)-5-[3′,3′,3′-²H₃]propyl-5-octen-4-ol ( 16 ), its (Z)-isomer 17 , and the corresponding [8,8,8-²H₃]-isomers 18 and 19 (see Scheme 1). The proportions of 4–7 were carefully determined by GC between 10% and 85% conversion of 1 and were constant within this range. The labeled substrate 2 was photooxygenated in two high-conversion experiments, and after reduction, the ratios 16/18 and 17/19 were determined by NMR. Isotope effects in 2 were neglected and the proportions of corresponding products from 1 and 2 assumed to be similar (% 4 ≈? % 14 ; % 5 ≈? % 15 ; % 6 ≈? % ( 16 + 18 ): % 7 ≈? % ( 17 + 19 )). Combination of these proportions with the ratios 16/18 and 17/19 led to an estimate of the proportions of hydroperoxides formed from 2 . Accordingly, singlet oxygen ene additions at the disubstituted side of 2 are preferred (ca. 90%). The previously studied trisubstituted olefins 20–25 exhibited the same preference, but had both CH₃ and higher alkyl substituents on the double bond. In these substrates, CH₃ groups syn to the lone alkyl or CH₃ group appear to be more reactive than CH₂ groups at that site beyond a statistical bias.     

Structure and formation of gaseous [C4H6O]+˙ ions: 1—The enolic ions [CH2C(OH)?CHCH2]+˙ and [CH2CH?CHCH(OH)]+˙ and their relationship with their keto counterparts

The [C₄H₆O]^+˙ ion of structure [CH₂?CHCH?CHOH]^+˙ (a) is generated by loss of C₄H₈ from ionized 6,6-dimethyl-2-cyclohexen-1-ol. The heat of formation ΔH_f of [CH₂?CHCH?CHOH]^+˙ was estimated to be 736 kJ mol^?1. The isomeric ion [CH₂?C(OH)CH?CH₂]^+˙ (b) was shown to have ΔH_f, ? 761 kJ mol^?1, 54 kJ mol^?1 less than that of its keto analogue [CH₃COCH?CH₂]^+˙. Ion [CH₂?C(OH)CH?CH₂]^+˙ may be generated by loss of C₂H₄ from ionized hex-1-en-3-one or by loss of C₄H₈ from ionized 4,4-dimethyl-2-cyclohexen-1-ol. The [C₄H₆O]^+˙ ion generated by loss of C₂H₄ from ionized 2-cyclohexen-1-ol was shown to consist of a mixture of the above enol ions by comparing the metastable ion and collisional activation mass spectra of [CH₂?CHCH?CHOH]^+˙ and [CH₂?C(OH)CH?CH₂]^+˙ ions with that of the above daughter ion. It is further concluded that prior to their major fragmentations by loss of CH₃˙ and CO, [CH₂?CHCH?CHOH]⁺˙ and [CH₂?C(OH)CH?CH₂]^+˙ do not rearrange to their keto counterparts. The metastable ion and collisional activation characteristics of the isomeric allenic [C₄H₆O]^+˙ ion [CH₂?C?CHCH₂OH]^+˙ are also reported.     

1H and 13C nuclear magnetic resonance study of (D3)-trishomocuban-4-ol and (D3)-trishomocubanone

The complete assignments of the ¹H and ¹³C NMR spectra for (D₃)-trishomocuban-4-ol (3) and (D₃)-trishomocubanone (4) are reported. The difference between the ¹H and ¹³C chemical shifts of 3 and 4 and those of the hydrocarbon (D₃)-trishomocubane, and the substituent effect of the hydroxy group, can be adequately explained by the unique stereochemistry of these compounds.     

The Electron Transfer Series [MoIII(bpy)3]n (n=3+, 2+, 1+, 0, 1−), and the Dinuclear Species [{MoIIICl(Mebpy)2}2(μ2‐O)]Cl2 and [{MoIV(tpy.)2}2(μ2‐MoO4)](PF6)2⋅4 MeCN

The electronic structures of the five members of the electron transfer series [Mo(bpy)₃]ⁿ (n=3+, 2+, 1+, 0, 1?) are determined through a combination of techniques: electro‐ and magnetochemistry, UV/Vis and EPR spectroscopies, and X‐ray crystallography. The mono‐ and dication are prepared and isolated as PF₆ salts for the first time. It is shown that all species contain a central Mo^III ion (4d³). The successive one‐electron reductions/oxidations within the series are all ligand‐based, involving neutral (bpy⁰), the π‐radical anion (bpy^.)^1?, and the diamagnetic dianion (bpy^2?)^2?: [Mo^III(bpy⁰)₃]³⁺ (S=3/2), [Mo^III(bpy^.)(bpy⁰)₂]²⁺ (S=1), [Mo^III(bpy^.)₂(bpy⁰)]¹⁺ (S=1/2), [Mo^III(bpy^.)₃] (S=0), and [Mo^III(bpy^.)₂(bpy^2?)]^1? (S=1/2). The previously described diamagnetic dication “[Mo^II(bpy⁰)₃](BF₄)₂” is proposed to be a diamagnetic dinuclear species [{Mo(bpy)₃}₂(μ₂‐O)](BF₄)₄. Two new polynuclear complexes are prepared and structurally characterized: [{Mo^IIICl(^Mebpy⁰)₂}₂(μ₂‐O)]Cl₂ and [{Mo^IV(tpy^.)₂}₂(μ₂‐Mo^VIO₄)](PF₆)₂?4 MeCN.     

两个三维柱层式单一手性配位化合物:合成、结构和性质（英文）

在溶剂热合成条件下得到2个单一手性配位聚合物,即[Cd3((R)-CIA)2(bipy)2.5(H2O)2]·xGuest(1)和[Zn3((R)-CIA)(bmib)2(H2O)2 Cl]·H2O·xGuest(2)((R)-H3CIA=(R)-5-(1-羧基乙氧基)间苯二甲酸,bipy=4,4′-联吡啶,bmib=1,4-双(2-甲基-1H-咪唑-1-基)苯)。X射线单晶结构分析揭示配合物1和2都是柱层式结构的三维框架。从拓扑分析的角度看,配位物1具有(3,3,3,6,6)-连接的网络,拓扑符号为(4.5^2)2(4.8^2)2(42.6^8.8^3.10^2)(4^2.6^8.8^3.9^2)(5.8.9)2,而配合物2是(3,4,4)-连接的网络,拓扑符号为(6·7^2)2(6·7^5)2(6^2·7^4)。此外,对上述配合物的热稳定性、圆二色谱和荧光性质也做了研究。     

Trifluoro­meth­yl derivatives of penta­cyclo­[5.4.0.02,6.03,10.05,9]undeca­ne

Three cage‐like polycyclic compounds, viz.exo‐8‐(trifluoro­meth­yl)­penta­cyclo­[5.4.0.0^2,6.0^3,10.0^5,9]undecan‐endo‐8‐ol, C₁₂H₁₃F₃O, 5‐(trifluoro­meth­yl)‐4‐oxahexa­cyclo­[5.4.1.0^2,6.0^3,10.0^5,9.0^8,11]­dodecan‐3‐ol, C₁₂H₁₁F₃O₂, and N‐[exo‐11‐(trifluoro­meth­yl)‐endo‐11‐(trimethyl­sil­yl­oxy)­penta­cyclo­[5.4.0.0^2,6.0^3,10.0^5,9]undecan‐8‐yl­idene]aniline meth­anol solvate, C₂₁H₂₄F₃NOSi·CH₄O, were obtained from the corresponding oxo derivatives by nucleophilic trifluoro­methyl­ation with (tri­fluorometh­yl)trimethyl­silane in 1,2‐dimethoxy­ethane solution in the presence of CsF. The crystal structures show that the addition of trifluoro­methanide occurs exclusively from the exo face of the polycyclic ketones. Further examination of the crystal structures, together with that of the starting penta­cyclo­[5.4.0.0^2,6.0^3,10.0^5,9]undecane‐8,11‐dione, C₁₁H₁₀O₂, showed that increasing substitution at the 8‐ and/or 11‐positions in the cage mol­ecules increases the non‐bonded intra­molecular C·C distances at the mouth of the cage and changes the puckering of the five‐membered rings involving the 8‐ and 11‐positions from an envelope towards a distorted half‐chair conformation. Inter­molecular co‐operative O—H·O hydrogen bonds in the endo‐8‐ol compound link the mol­ecules into tetra­mers.     

Crystal structure of LiFe3+(SeO3)2

Summary Single crystals of LiFe³⁺(SeO₃)₂ were prepared by hydrothermal synthesis. The crystal structure of LiFe³⁺(SeO₃)₂ is reported: tetragonal, space group I 2d,a=10.649(2) Å,c=9.959(2) Å,V=1129.4 ų,Z=8, 1268 unique reflections,R=0.037. The structure contains LiFeO₈ groups, built up by FeO₆ octahedra edgesharing with strongly distorted LiO₄ tetrahedra. These LiFeO₈ groups share corners with trigonal pyramidal SeO₃ groups to form a three dimensional network. The mean bondlengths are 1.994 Å, 2.006 Å and 1.699 Å for Li-O, Fe-O and Se(IV)-O, respectively.

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Die Kristallstruktur von LiFe³⁺(SeO₃)₂

Zusammenfassung Einkristalle von LiFe³⁺(SeO₃)₂ wurden auf hydrothermalem Weg dargestellt und ihre Kristallstruktur bestimmt: tetragonal, Raumgruppe I 2d,a=10.649(2) Å,c=9.959(2) Å,V=1129.4 ų,Z=8, 1268 unabhängige Reflexe,R=0.037. Kennzeichnend für die Atomanordnung sind LiFeO₈ Gruppen, die aus FeO₆ Oktaedern und mit ihnen kantenverknüpften, stark verzerrten LiO₄ Tetraedern aufgebaut sind. Diese LiFeO₈ Baueinheiten bilden, mit trigonal pyramidalen SeO₃ Gruppen über Ecken verbunden, ein dreidimensionales Netzwerk. Die Mittelwerte der Li-O, Fe-O and Se(IV)-O Abstände sind 1.994 Å, 2.006 Å und 1.699 Å.

     

A 3D Luminescent Metal‐organic Framework Constructed from Cu4I4 Cubane Clusters and Triangular Imidazole Ligand

Abstract . The solvothermal reaction between cuprous iodide and the rigid triangular imidazole ligand in mixed N,N′‐dimethylacetamide (DMA)‐acetonitrile solvent leads to the isolation of the 3D metal‐organic framework [(Cu₄I₄)₃(TIPA)₄] · 7DMA ( 1 ) [TIPA = tri(4‐imidazolylphenyl) amine], which was characterized by elemental analysis, IR spectroscopy, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. Topologically, the structure of 1 is an unprecedented 3,3,4,4‐connected net with a point symbol of {4.8.10}₂{4.8²}₂{4².8².10²}₂{8⁴.12²}. Compound 1 exhibits orange‐red photoluminescence with an emission maximum at 622 nm at room temperature.     

Base Hydrolysis of Pentaaminecobalt (III) Complexes: The [CoX(dien) (dapo)]n+ system. Part 3. The internal conjugate base mechanism

Azide anation and racemization of optically pure mer-exo(H)- and mer-endo(H)-[Co(OH)(dien)(dapo)]²⁺ ( A and B (X = OH), resp.; dien = N-(2-aminoethyl)ethane-1,2-diamine; dapo = 1,3-diaminopropan-2-ol) involve the same symmetrical pentacoordinate intermediate as the base hydrolyses of the corresponding mer-exo(H)- and mer-endo(H)-[CoX(dien)(dapo)]²⁺ species A and B , respectively, where X = Cl, Br, or N₃. The kinetic parameters of the anation process are fully compatible with the independently measured competition ratio. The rate data reveal that substitution of OH^? is unexpectedly fast, viz. it is not consistent with the usual sequence Br^? > Cl^? > H₂O > N > OH^?. This behavior is interpreted on the basis of an internal conjugate base mechanism which involves an amino-hydroxo/aminato-aqua tautomerism, viz. the reaction is actually an OH^? -catalyzed substitution of [CoH₂O(dien)(dapo)]³⁺ where deprotonation occurs effectively at the secondary-amine site NH of dien.     

Codimerization of quadricyclane withendo,exo-hexacyclo[9.2.1.02,10.03,8.04,6.05,9]tetradec-12-ene catalyzed by the Pd(PPh3)4 complex

endo,exo-Hexacyclo[9.2.0^2,10.0^3,8.0^4,6.0^5,9]tetradec-12-ene (1) undergoes cyclocodimerization with quadricyclane (Q) in the presence of the Pd(PPh₃)₄ complex to giveexo,exo,endo,exo-decacyclo[9.9.1.0^2,10.0^3,8.0^4,6.0^5,9.0^12,20.0^13,18.0^14,16.0^15,19]heneicosane (2) andendo,exo,endo,exo-decacyclo[9.9.1.0^2,10.0^3,8.0^4,6.0^5,9.0^12,20.0^13,18.0^14,16.0^15,19]heneicosane (3) in a ratio of 10 7 (yield up to 26 %). Simultaneously, homocyclotrimerization of Q occurs to give three known C₂₁ hydrocarbons (4–6). The yields of compounds2 and3 and the selectivity of the process depend considerably on the reaction conditions and the molar ratio of1 and Q. Compounds2 and3 that were obtained were characterized by¹³C NMR spectra.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1983–1985, November, 1994.     

Synthese und Strukturuntersuchung von Zn3Ta2O8

Zn₃Ta₂O₈ was prepared by high temperature solid state reaction (CO₂-Lasertechnique). X-ray investigations of single crystals yield monoclinic symmetry (a=9.499;b=8.411;c=8.881 Å; =116.03°, space group C _2h ⁶ —C2/c). There is no relationship between Zn₃Ta₂O₈ and Zn₃Nb₂O₈. Zn₃Ta₂O₈ shows a characteristic structure type with octahedral coordination of Ta⁵⁺ and tetrahedral coordination of Zn²⁺.

     

Conformations of the Ten-membered Ring in 5, 10-Secosteroids. III: (Z)-3β- and (Z)-3α-Hydroxy-5, 10-seco-1 (10)-cholesten-5-one Esters and (Z)-5, 10-seco-1 (10)-Cholestene-3, 5-dione

(Z)-3β-Acetoxy- and (Z)-3 α-acetoxy-5, 10-seco-1 (10)-cholesten-5-one ( 6a ) and ( 7a ) were synthesized by fragmentation of 3β-acetoxy-5α-cholestan-5-ol ( 1 ) and 3α-acetoxy-5β-cholestan-5-ol ( 2 ), respectively, using in both cases the hypoiodite reaction (the lead tetraacetate/iodine version). The 3β-acetate 6a was further transformed, via the 3β-alcohol 6d to the corresponding (Z)-3β-p-bromobenzoate ester 6b and to (Z)-5, 10-seco-1 (10)-cholestene-3, 5-dione ( 8 ) (also obtainable from the 3α-acetate 7a ). The ¹H-and ¹³C-NMR. spectra showed that the (Z)-unsaturated 10-membered ring in all three compounds ( 6a , 7a and 8 ) exists in toluene, in only one conformation of type C ₁, the same as that of the (Z)-3β-p-bromobenzoate 6b in the solid state found by X-ray analysis. The unfavourable relative spatial factors (interdistance and mutual orientation) of the active centres in conformations of type C ₁ are responsible for the absence of intramolecular cyclizations in the (Z)-ketoesters 6 and 7 ( a and c ).     

Phase behaviour of 1-hexyloxymethyl-3-methyl-imidazolium and 1,3-dihexyloxymethyl-imidazolium based ionic liquids with alcohols,water, ketones and hydrocarbons: The effect of cation and anion on solubility

The liquid–liquid equilibrium (LLE), or solid–liquid equilibrium (SLE) of more than 20 binary systems containing 1-hexyloxymethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)-imide [C₆H₁₃OCH₂MIM][Tf₂N] with alcohol (butan-1-ol, or hexan-1-ol, or octan-1-ol), water and ketone (3-pentanone, or cyclopentanone) and of 1-hexyloxymethyl-3-methyl-imidazolium tetrafluoroborate [C₆H₁₃OCH₂MIM][BF₄] with alcohol (methanol, or ethanol, or butan-1-ol, or hexan-1-ol, or octan-1-ol), water and ketone (3-pentanone, or cyclopentanone) have been measured. The solubility of dialkoxy-imidazolium salts: (1) 1,3-dihexyloxymethyl-imidazolium bis(trifluoromethylsulfonyl)-imide [(C₆H₁₃OCH₂)₂IM][Tf₂N] in alcohol (butan-1-ol, or hexan-1-ol, or octan-1-ol, or decan-1-ol), in water and hydrocarbon (benzene, hexane and cyclohexane); (2) 1,3-dihexyloxymethyl-imidazolium tetrafluoroborate [(C₆H₁₃OCH₂)₂IM][BF₄] in alcohol (hexan-1-ol, or octan-1-ol, or decan-1-ol) and water have been measured. Measurements were carried out by using a dynamic method from T = 275 K to the boiling point of the solvent. In this work a systematic study of the impact of different factors on the phase behaviour of hexyloxy-imidazolium-based ionic liquids with polar and nonpolar solvents has been presented. Most of the examined systems showed immiscibility in the liquid phase with an upper critical solution temperature (UCST), or complete solubility of the ionic liquid at room temperature in many solvents. An increase in the alkyl chain length of alcohol resulted in an increase in the UCST. The choice of anion was shown to have large impact on the solubility: by changing the anion [Tf₂N]⁻ to [BF₄]⁻, the solubility dramatically decreased and the UCST increased. By contrast, increasing hydrogen bonding opportunities with the solvent by replacing a methyl group with the second alkoxy-group on the imidazolium ring results in an increase of the solubility.     

Heterodiamantane und strukturell verwandte Verbindungen. III.. Pentacyclische diäther der C11-reihe. 5, 13-Dioxapentacyclo-[6.5.0.02,6.03,12.04,9]tridecan, 4, 13-dioxapentacyclo [6.4.1.02,7.03,10.05,9]tridecan und 3, 10-dioxapentacyclo [7.3.1.02,7.04,12.06,11]tridecan

Heterodiamantanes and Structurally Related Compounds. Part III. The Pentacyclic C₁₁-Diethers 5, 13-Dioxapentacyclo [6.5.0.0^2,6.0^3,12.0^4,9]tridecane, 4, 13-Dioxapentacyclo [6.4.1.0^2,7.0^3,10.0^5,9]tridecane, and 3, 10-Dioxapentacyclo [7.3.1.0^2,7.0^4,12.0^6,11]tridecane In connection with the studies on heterodiamantanes and structurally related compounds the three novel pentacyclic diethers 3 – 5 were prepared starting from the cyclopentadienone dimer 6 . All four compounds have as common features a central carbocyclic 6-membered ring with four axial alkyl substituents and two oxygen functions in 1, 4 position. The required eleventh C-atom was introduced by dichlorocarbene addition either to 6 ( → 7 ) (Scheme 2) or to 29 ( → 28 ) (Scheme 4). Diether 3 was obtained by reduction of 26 (Scheme 2), a suitable precursor prepared either by intramolecular addition ( 24 → 26 ; Scheme 2) or substitution ( 30 → 26 , 31 → 26 ; Scheme 4), as well as by direct substitution ( 44 → 3 , 42 → 3 ; Scheme 5). Diether 4 was the product of a direct substitution ( 39 → 4 , 36 → 4 ; Scheme 5). The synthesis of diether 5 was achieved from the addition product 51 (resulting from the alcohols 47 and 48 ; Scheme 6). Diether 4 is the thermodynamically least stable of the three diethers 3 – 5 . It was easily isomerized to 5 on treatment with concentrated sulfuric acid in benzene whereas 3 and 5 remained unchanged under these conditions.     

Topological analysis of the three‐dimensional coordination polymer poly[(μ4‐azido)[μ4‐5‐(pyridin‐4‐yl)tetrazolido]disilver(I)]

The title compound, [Ag₂(C₆H₄N₄)(N₃₎]_n, was obtained under hydrothermal conditions at 433 K. The asymmetric unit of the orthorhombic space group (Pna2₁) consists of two Ag⁺ cations, an anionic 5‐(pyridin‐4‐yl)tetrazolide (4‐ptz⁻) ligand and an anionic azide ligand. Both Ag⁺ centres are coordinated by four N atoms, forming a distorted tetrahedral coordination environment. When all the component ions are viewed as 4‐connected nodes, the whole three‐dimensional network can be regarded topologically as a new kind of 4,4,4,4‐connected net with the Schläfli symbol (4.8⁵)(4².8⁴)(4³.8³)₂.     

Synthesis and X-ray crystal structures of bis(3-hydroxy-4-methyl-2(3H)-thiazolethiolato-S 2,O)bis(dimethylsulfoxide-O)M,M = cobalt(II) and nickel(II)

Crystallisation of the divalent nickel and cobalt complexes of 3-hydroxy-4-methyl-2(3H)-thiazolethione (HMTT) from DMSO yields isostructural chelate complexes M(MTT)₂(dmso)₂, M = Co^II/Ni^II. The metal atom adopts distorted octahedral coordination via two bidentate MTT ligands arranged in a trans-conformation and two DMSO molecules coordinated through oxygen. Powder X-ray diffraction (PXRD) and energy-dispersive X-ray (EDX) analysis show that the materials form a continuous solid solution Co _x Ni_1–x (MTT)₂(dmso)₂ over the entire composition range 0 x 1.     

The He(Iα) Photoelectron Spectra of the Perfluoroderivatives of Trisannelated Benzenes and Tetrakisannelated Cyclooctatetraenes

The He(Iα) photoelectron (PE) spectra of tris(perfluorocyclobuta)benzene 4 (F)

1 3,3,4,4,7,7,8,8,11,11,12,12-Dodecafluorotetracyclo[8.2.0.0^2,5.0^6,9]dodeca-1,5,9-triene

, tris(perfluorocyclopenta)benzene 5 (F)

2 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-Octadecafluoro-2,3,4,5,6,7,8,9-octahydro-1H-trindene.

, tetrakis(perfluorocyclobuta)cyclooctatetraene 6 (F)

3 3,3,4,4,7,7,8,8,11,1l,l2,l2,l5,15,16,16-Hexadecafluoropentacyclo[12.2.0.0^2,5.0^6,9.0^10,13]hexadeca-1,5,9,13-tetraene.

, and of tetrakis(perfluorocyclopenta)cyclooctatetraene 7 (F)

4 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12-Tetracosafluoro-1,2,3,4,5,6,7,8,9,10,11,12-dodeca-hydrotetracyclopenta[a,c,e,g]cyclooctene.

are reported. A tentative assignment of the PE spectra is derived by empirical correlation with those of relevant reference compounds. The results suggest that 6 (F) retains the D_4h-conformation in the gas phase, i.e. A conformation with a planar cyclooctatetraene ring, as observed in the crystal. All four compounds exhibit a sharp increase of their first ionization energies, relative to the corresponding parent hydrocarbons, due to the perfluoro effect.