bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organometallic Group‐13 Metal Complexes of d‐Block Elements, XIV. Intramolecularly Base‐adduct‐stabilized Transition‐metal‐substituted Indanes: Synthesis and Spectroscopic Characterization, Structure of (η5‐C5H5)(CO)NiInBr2(NC7H13)
Authors: Weiß Jurij , Frank Alissa , Herdtweck Eberhardt , Nlate Sylvain , Mattner Mike , Fischer Roland A. 
Published: July 2007

AbstractThe reaction of InBr/InBr3 or InBr/BrIn[(CH2)3NMe2]2 with the transition metal dimers [L(CO)nM]2 {L = CO, Cp, C5H4[(CH2)2NMe2]; M = Fe, Co, Ni; n = 1–3} in THF or dioxane gives in almost quantitative yield the transition metal indium complexes L(CO)nMInBr2(Do) (Do = THF, NC7H13) and L(CO)nMIn[(CH2)3NMe2](Br) respectively. The new compounds were characterized by elemental analysis, infrared v(CO) spectroscopy, NMR, and mass spectrometry. An X‐ray single crystal structure determination of (η5‐C5H5)(CO)‐Ni–InBr2(NC7H13) (1a) revealed a short Ni–In bond of 246.3(1) pm.
Improved Access to {[ω‐(Phosphanyl)alkyl]cyclopentadienyl}cobalt(I) Complexes: Decomplexation of the Phosphane Arm; Alkyne Complexes; Synthesis of Mononuclear Vinylidenecobalt(I) Complexes
Authors: Foerstner Jan , Kettenbach Ralf , Goddard Richard , Butenschön Holger 
Published: July 2007

AbstractAn improved synthesis of [(2‐phosphanylethyl)cyclopenta‐dienyl]cobalt(I) chelate complexes is presented, in which the paramagnetic chloride 3 is a precursor of the ethene complex 4. The latter readily undergoes ligand exchange reactions which in the case of bidendate reagents (1,5‐cyclooctadiene, 1,2‐bis(diisopropylphosphanyl)ethane, 2,2′‐bipyridine, nor‐bornadiene) cause a decomplexation of the phosphane arm at room temperature with formation of 7, 5, 6, 8. The ethene ligand in 4 can be replaced by alkynes under equally mild reaction conditions (formation of 9, 11 – 16). The reaction with ethyne results in the formation of vinylidene complex 10. The yields of the reactions with nonaromatic alkynes could be improved by treating 3 with the alkyne in the presence of sodium amalgam. The unsubstituted vinylidene complex 10 and its tert‐butyl derivative 17 were obtained by this route in 38 and 40% yield, respectively.
Metal Complexes of Biologically Important Ligands, LXXXVI. Organometallic Complexes of Ruthenium(II), Rhodium(III), Iridium(III), and Gold(I) with Cinchona Alkaloids
Authors: Missling Christopher , Mihan Shahram , Polborn Kurt , Beck Wolfgang 
Published: July 2007

AbstractThe following chiral organometallic complexes of the cinchona alkaloids quinine (L1), cinchonidine (L2), quinidine (L3), cinchonine (L4) were prepared: [(η5‐C5H5)(Ph3P)(OC)‐Ru(L)]BF4 (1: L=L1; 2: L=L2; 3: L=L3), ClAuL1 (4), [(η5‐C5Me5)(Cl2)Ir(L)] (5: L=L1; 6: L=L2; 7: L=L4), [(η5‐C5Me5)(Cl2)Rh(L2)] (8), [(η6‐p‐cymene)(Cl2)Ru(L)] (9: L=L1; 10: L=L2; 11: L=L4). In all complexes the tertiary nitrogen atom of the cinchona alkaloids is bound to the metal. Complexes 5 – 11 are formed as mixtures of isomers. Elimination of HCl from 10 and 11 gives the neutral N,O‐chelate complexes (η6‐p‐cymene)(Cl)Ru(L2 – H+) (13) and (η6‐p‐cymene)‐(Cl)Ru(L4 – H+) (14) which were structurally characterized by X‐ray diffraction.
(Iminoboryl)borate [R3BBNR]−: Durch Elektrophile E induzierte Umlagerung zu (Aminoboryl)boranen R2BBRNRE
Authors: Luckert Stefan , Englert Ulli , Paetzold Peter 
Published: July 2007

(Iminoboryl)borates [R3BBNR]−: Rearrangement to (Aminoboryl)boranes R2BBRNRE by the Addition of Electrophiles E(Iminoboryl)borates [Li(tmeda)2][R2R′B–BNR (2a–c, R′ = Me, Me3SiCH2, Me3CCH2) are formed from the azadiboriridine NB2R3 (1, R = tBu) and LiR′ in the presence of tmeda. Vinyllithium brings about a ring expansion of 1 to give the five‐membered anionic ring [–CHCH–BRNR–BHR–]–, to which [Li(tmeda)]+ is bound (3). The (aminoboryl)boranes R2B–BMeNER (4a–c, EX = HCl, MeI, Me3SiI) are obtained, when the polar compounds EX are added to 2a, accompanied by the elimination of LiX and the migration of Me. The borate 2b reacts with HCl to give a mixture of the isomers R2B–B(CH2SiMe3)=NHR (4d) and R(Me3SiCH2)‐B–BR=NHR (4d′), and 2c reacts with HCl to yield the borane R(Me3CCH2)B–BR=NHR (4e′) exclusively. The transformation of [R2R′B–BNR]‐ to R2B–BR′ = NRE by the attack of electrophiles E corresponds to the known transformation of [R′3B–CR″] to R′2B–CR′=CR″E.
Reaction of the Alkylindium(I) Compound In4[C(SiMe3)3]4 with Octacarbonyldicobalt: Bridging of the CoCo Bond by one or two InC(SiMe3)3 Groups
Authors: Uhl Werner , Keimling Sven Uwe , Hiller Wolfgang , Neumayer Markus 
Published: July 2007

Abstracttetrahedra‐Tetrakis[tris(trimethylsilyl)methyl]tetraindane(4) (1) reacts with octacarbonyldicobalt to yield two products, depending on the stoichiometric ratio of the starting compounds: By replacement of one bridging carbonyl group a dicobalt monoindium derivative 2 is formed, which contains a CoCo bond [256.81(5) pm] bridged by one carbonyl and one monoalkylindium group. While 2 is a monomer in benzene solutions, it dimerizes in the solid state by an interaction of the oxygen atom of the bridging carbonyl group to the coordinatively unsaturated In atom of a second molecule across a center of symmetry. Another compound (3) is formed by the replacement of both bridging carbonyl ligands, which exhibits a strongly distorted Co2In2 tetrahedron with normal CoIn bond lengths of 253.44(6) pm, but long CoCo [280.14(6) pm] and InIn distances [336.18(6) pm].
8‐quinolylcyclopentadienyl, a ligand with a tailored fit for chelate complexes
Authors: Enders Markus , Rudolph Ralph , Pritzkow Hans 
Published: July 2007

Abstract8‐Lithioquinoline reacts with 2,3,4,5‐tetramethylcyclopentenone to give 8‐quinolylcyclopentadiene (1/2) after acidic workup and treatment with ammonia. Two of the possible three isomers are formed; the acidic protons on the Cp rings show unusual downfield shifts in the 1H‐NMR spectra. Treatment with strong bases led to the intensely coloured anionic 4 which was converted into the trimethylsilyl derivative 5. This is a suitable starting compound for the trihalotitanium and ‐zirconium compounds 6 and 7. The two complexes were investigated by crystal structure analyses. In both cases the quinolyl nitrogen atom is coordinated to the metal.
Reactions of diaminophosphenium and 1,3,2‐diazaphospholenium triflates with silver salts
Authors: Gudat Dietrich , Holderberg Andreas W. , Kotila Sirpa , Nieger Martin 
Published: July 2007

AbstractReaction of bis(diisopropylamino)phosphenium triflate (1[CF3SO3]) with silver salts AgY [Y– = CF3CO2– (2a), CF3‐SO3– (2b), CH3CO2– (2c)] affords neutral complexes [{(iPr2N)2(Y)P} Ag(OSO2CF3)] (3a–c). While 3a, c are stable up to ambient temperature, 3b is only stable at low temperature and in equilibrium with the cation 1. The constitution of 3a–c was derived from multinuclear (1H, 13C, 31P, 109Ag) NMR spectra. Compound 3a was further studied by X‐ray single‐crystal diff ractommetry which showed the presence of dimeric units with μ2‐bridging triflate ligands and three‐coordinate silver atoms with a planar T‐shaped coordination geometry. Reaction of 4‐chloro‐1,3‐bis(2,6‐dimethylphenyl)‐1,3,2‐diazaphospholenium triflate (4[CF3SO3]) with 2a, c affords equilibrium mixtures whose 31P‐ and 109Ag‐NMR spectra suggested the presence of silver complexes 5a, c with constitutions similar to those of 3a, c besides unreacted cation 4. No reaction was observed between 4[CF3SO3] and 2b. A common mechanism accounting for the different outcome of the individual reactions will be discussed.
Über das Silaethen tBu2SiC(SiMe3)2 und die Struktur sowie Reaktivität seines [4 + 2]‐Cycloaddukts mit Ph2CO
Authors: Wiberg Nils , Hwang‐Park Hae‐Sook , Lerner Hans‐Wolfram , Dick Stefan 
Published: July 2007

On the Silaethene tBu2Si=C(SiMe3)2, and the Structure and Reactivity of Its [4 + 2] Cycloadduct with Ph2C=OFrom tBu2SiFCLi(SiMe3)2 by LiF elimination only Me2Si= C(SiMe3)(SiMetBu2) (1b) instead of tBu2Si=C(SiMe3)2 (1a) is isolated. With benzophenone, silaethene 1b (from its THF adduct 1b · THF) forms at –78 °C a yellow [4 + 2] cycloadduct (5) and a colorless [2 + 2] cycloadduct (6). With increasing temperature 5 transforms into 6, and 6 transforms –more slowly – into the yellow [4 + 2] cycloadduct (7) of 1a and Ph2CO. It follows from this that the migration equilibrium 1a ⇄ 1b really exists. The structure of 7 shows a planar OCPhC6H5–framework with the cycloadded atoms Si and C from –tBu2SiC(SiMe3)2– located above the plane. The =C6H5C bond (1.62 Å) is exceptionally long. 7 is a source for 1a which is trapped by acetone (formation of an ene product) and by benzaldehyde [formation of a [2 + 2] cycloadduct, unstable against cycloreversion into PhHC=C(SiMe3)2 and tBu2SiO‐containing substances]. Reaction of 7 with trimethylsilyl azide, less reactive than acetone or benzaldehyde, leads – by way of 1a which transforms into 1b – to a trapping product of 1b (formation of a [3 + 2] cycloadduct, unstable against transformation into (RMe2Si)(Me3Si)CN2 with R = (Me3Si)2N, or cycloreversion into (tBu2MeSi)(Me3Si)CN2 and Me2SiNSiMe3‐containing substances). Reaction of 1b or 1b · THF with acetone leads only to an ene reaction product of 1b. This means, that only undetectable amounts of 1a or 1a · THF are in equilibrium with 1b or 1b · THF. A minor substance which is shown by NMR at low temperatures besides 1b or 1b · THF is interpreted as a rotamer of 1b or 1b · THF.
The Synthesis of Stabilized Dimetallated Thioimidate Complexes by the Insertion of Ethoxycarbonylisothiocyanate into a Rhenium–Rhenium Bond
Authors: Adams Richard D. , Huang Mingsheng 
Published: July 2007

AbstractMolecules containing dimetallated hydrocarbyl groupings are of great chemical interest[1–3]. These groupings often represent intermediates in important catalytic processes[4]. Recently, we have shown that substituted dimetallated olefins can be formed by alkyne insertion into the metal–metal bonds of certain dinuclear complexes[2,5]. Complexes having dimetallated hydrocarbyl groups combined with heteroatoms are quite rare[6]. Herein is described the formation of a dimetallathioimidate grouping by the insertion of an organic isothiocyanates into an unsupported metal–metal bond. Organic isothiocyanates are useful reagents in organic synthesis[7], but the organometallic chemistry of these molecules is not yet well developed[8].
Organophosphorus Compounds, 112. Lewis Acid Mediated Spirocyclotrimerization of Kinetically Stabilized Phosphaalkynes – Key Step for the Selective Generation and Trapping of Triphospha Dewar Benzenes
Authors: Breit Bernhard , Regitz Manfred 
Published: July 2007

AbstractIn the presence of Lewis acidic derivatives of group 13 elements, phosphaalkynes 7 undergo spirocyclotrimerization with incorporation of the corresponding Lewis acids to form 10a–f. Scope and limitations of this novel cyclooligomerization process are examined. Starting from the spirocyclotrimer 10a reaction with the Lewis base dimethyl sulfoxide, we have in hand for the first time a method for the selective generation of two isomeric triphospha Dewar benzene derivatives (18, 19). Both can be trapped efficiently by further reaction with the phosphaalkyne to furnish the two novel phosphaalkyne cyclotetramers 20 and 21, both still possessing a phosphorus–carbon double bond. In the case of 21, further functionalization of the phosphaalkene unit is possible by [3 + 2] cycloaddition with a nitrile oxide (→ 23).
Ethyloboration of Selenium Dioxide and Selenium Bis(tert‐butylimide) – Molecular Structure of an Organo‐Substituted Eight‐Membered [–BOSeO–]2 Heterocycle
Authors: Köster Roland , Schüßler Wilhelm , Boese Roland , Herberhold Max , Gerstmann Silke , Wrackmeyer Bernd 
Published: July 2007

AbstractBoth selenium dioxide (1) and selenium bis(tert‐butylimide) (2) react with triethylborane (A) by 1,2‐ethyloboration. In the case of 1, ethane, ethene, diethylselane (4a), tetraethyldiboroxane (Et2B)2O (B), triethylboroxine (EtBO)3 (D) and a cyclic compound [–Et2BOSe(Et)O–]2 (52) are formed after heating to 65°C. Compound 52 is also formed when 1 reacts with B. Treatment of selenous acid (3) with A or, preferentially for synthetic purposes, with B provides further routes to 52. The reaction of the diimide 2 with A starts already below –50°C: a cyclic ethaneselenic acid derivative 6, Et2BN(tBu)‐Se(Et)NtBu, is formed, and 6 starts to decompose at –50°C by elimination of ethene to give finally (tert‐butylamino)diethylborane (8), bis(diethylboryl)‐tert‐butylamine (9), and Et2Se (4a). Transborylation of 52 with (9‐BBN)2O (C) affords [–(9‐BBN)OSe(Et)O–]2 (102), which crystallizes in the monoclinic space group P21/n with the lattice constants (118 K) a = 667.1(1), b = 1282.5(1), c = 1289.1(1) pm and β = 93.06(1)°. All reactions were monitored by 11B‐ and 77Se‐NMR spectroscopy. Furthermore, the reactions of 1 with A and B and the transborylations were studied by 17O‐NMR spectroscopy using the 17O‐enriched compounds 1(17O), B(17O), C(17O), and D(17O).
Transition Metal Complexes with Sulfur Ligands, Part 119. Synthesis of Water Soluble Fe and Ru Complexes with Novel Multidentate Thioether Thiolate Ligands Containing Carboxylate Substituents
Authors: Sellmann Dieter , Becker Thomas , Knoch Falk 
Published: July 2007

AbstractIn search of water soluble transition metal complexes with sulfur dominated coordination spheres that model key reactions of nitrogenases, the benzenedithiol derivatives ‘CO2HS2’‐H2 (1) and ‘CO2Me‐S2’‐H2 (2) were synthesized as precursors for multidentate sulfur ligands. The template alkylation of 2 by C2H4Br2 at [Fe(CO)2] fragments yielded a mixture of two diastereomeric C2 symmetrical [Fe(CO)2(‘CO2Me‐S4’)] complexes (4a and 4b), which were separated by crystallization. The hydrolysis of the mixture of the diastereomers 4a and 4b led to the isomerically pure tetradentate thioether thiol ligand ‘CO2Me‐S4’‐H2 (5) proving the regioselectivity of the template alkylation of the asymmetrical dithiol 2. The C1 symmetrical [Fe(‘CO2Me‐S2’)2]2‐ anion is an intermediate of the template alkylation and was isolated as (AsPh4)2 [Fe(‘CO2Me‐S2’2] (11), 4a, 5 and 11 were characterized by X‐ray structural analysis. Saponification of the methyl ester groups of 5 yielded ‘CO2H‐S4’‐H2 (7). Treatment of 7 with FeCl2 · 4 H2O in the presence of CO and LiOMe gave a mixture of two C2 symmetrical and water soluble diastereomers of Li2[Fe(CO)2(‘CO2‐S4’)] (8). Upon treatment with [RuCl2 (PPh3)3] 7 yielded isomerically pure [Ru(PPh3)2‐(‘CO2H‐S4’)] (9). 9 also exhibits C2 symmetry and could be reversibly deprotonated to form the water soluble complex K2[Ru(PPh3)2 (‘CO2‐S4’)] (10). Treatment of (NBu4)2 (‘CO2MeS2’) with “Ru(NO)Cl3” led to isomerically pure (NBu4)[Ru(NO)(‘CO2Me‐S2’)2] (12).
Contribution to the Chemistry of Boron, 232. Formation, Structure and Reactions of a P,P′‐Bi(1,3,2,4‐diphosphadiboretane)
Authors: Kaufmann Bernhard , Nöth Heinrich , Paine Robert T. 
Published: July 2007

AbstractPhotolysis of the 1,3,2,4‐diphosphadiboretane (tBuPBtmp)2 (1) in dilute toluene solution yields the bicyclic diphosphadiboretane 2. In concentrated toluene solution or in hexane, however, the P,P′‐connected bi(diphosphadiboretane) 4 is also formed implying that the radical [tBuP(Btmp)2P] 3 is the first photolysis product. On further photolysis, 3 and 4 are converted into bicyclic 2 as the final product. Reduction of 4 with sodium‐potassium alloy followed by silylation with Me3‐SiCl leads to the 1,3,2,4‐diphosphadiboretanes (tmpBP‐SiMe3)2 and [HP(Btmp)2PSiMe3]2. In contrast to many 1,3,2,4‐diboretanes, 4 in the absence of photon or thermal promotion does not react with Cr(CO)5 · THF, Fe2(CO)9, or Pd(PPh3)4. However, a mixture of Cr(CO)5 · THF and 4 on photolysis gives the known complex (tmpBP)2 · 2 Cr(CO)5.
Silver(I) Complex of a Crown Thioether Retaining the Transoid S–C–C–S Ligand Conformation
Authors: Gleiter Rolf , Röckel Harald , Nuber Bernhard 
Published: July 2007

AbstractThe crown thioether 3 with the novel diisopropylidene building block was synthesized by an S′N cyclization reaction of 2,7‐dichloro‐2,7‐dimethylocta‐3,5‐diyne (1) with 3‐thia‐pentane‐1,5‐dithiol (2). Ligand 3 shows all the sulfur centers in exodentate positions. Reaction of 3 with Ag1 triflate and triphenylphosphane yielded the tetrahedral complex 4, which shows unique spectroscopic data in solution. Crystallization furnished two different crystal forms (4a and 4b). Both are different conformers which are stable in the solid state. 4a exhibits a crown‐like structure of the thioether ligand with cisoid SCCS chains. To our knowledge 4b is the first silver(1) complex with a crown thioether retaining the tran‐soid SCCS conformation in the metal complex.
Gold(I) and Silver(I) Complexes with Methanide Ligands [C{PPh2(X)}3]– (X = O, S). Crystal Structures of [M{C(PPh2(X))3}(PPh3)] (M  Au, X  O; M  Ag, X  S)
Authors: Gimeno M. Concepción , Jones Peter G. , Laguna Antonio , Villacampa M. Dolores 
Published: July 2007

AbstractMetal complexes (M(acac)(PPh3)] act as deprotonating agents in the reaction with equimolar amounts of [CH{PPh2(X)}3)] to give the neutral complexes [M{C(PPh2(X))3}(PPh3)] [M = Ag, X = O (1) or S (2); M = Au; X = O (3) or S (4)]. The crystal structures of 2 and 3 have been established by X‐ray crystallography. In the structure of 2 (two independent molecules) the silver(I) atoms display a distorted tetrahedral coordination by phosphorus (of PPh3) and three sulfur atoms. In complex 3 the gold(I) atom exhibits linear coordination by phosphorus of PPh3 and the carbon atom of [C{PPh2 (O)}3]‐. The reaction of [CH{PPh2(X)}3] with [Ag(CF3SO3)] or [Ag(CF3SO3)(PPh3)] (molar ratio 1:1) leads to [Ag(CF3SO3){CH(PPh2(X))3}] [X = O (5), S (6)] or [Ag(CH(PPh2 (S))3}(PPh3)](CF3SO3) (7), respectively.
The Chemistry of Metallacyclic Alkenylcarbene Complexes, 4. Unsaturated Metallacyclic Carbene Complexes as Flexible Tools in Organic Synthesis. Novel Rearrangement and Cascade Pathways to Functionalized Alkadienes, Carbo‐, and Heterocycles
Authors: Schobert Rainer 
Published: July 2007

AbstractCationic metallacyclic carbene complexes of iron and cobalt bearing a terminal η3‐allyl ligand are susceptible to nucleophilic attack at different sites depending on the particular set of substituents, the central metal fragment, and the nucleophile. Attack of enolates, cuprates, acetylides, or heteroatom nucleophiles like phosphanes at the metallacyclic perimeter of the iron complexes 18 provides an easy access to unsaturated organic products like 1,2‐ or 1,3‐dienes, δ‐lactones, and functionalized cyclopentenones through novel rearrangement or cascade pathways. Synthetic applications are described; factors governing reactivity/selectivity are discussed; X‐ray analytical structures of novel metallacycles are provided.
Ring Expansion of Spirocyclic Cyclobutenylidene Ligands in Pentacarbonylchromium Complexes to Tetrahydroindene Derivatives
Authors: Fischer Helmut , Karl Christoph C. , Roth Gerhard 
Published: July 2007

AbstractPentacarbonyl(pentamethylenevinylidene)chromium, [(CO)5CrCC(CH2)5] (1), reacts with 1‐methylthio‐1‐propyne (2a) and N‐(1‐propynyl)phenothiazine (2b) by regio‐specific addition of the CC bond of the alkyne to the CC bond of the vinylidene ligand of 1. Initially, complexes with a spirocyclic cyclobutenylidene ligand are formed, [(CO)5Cr(CH2)5] (3) and [(CO)5‐Cr(CH2)5] (10). Subsequent thermally initiated ring expansion affords the 2‐methyl‐4,5,6,7‐tetrahydroindenyl(methyl)thioether complex [(CO)5‐Cr–S(Me)(Me‐C9H10)] (4) and the N‐(2‐methyl‐4,5,6,7‐tetrahydroindenyl)phenothiazine complex [(CO)5Cr–S(C6H4)2‐N–(Me‐C9H10)] (11), respectively. In both complexes, 4 and 11 the ligand is coordinated to the metal via the sulfur atom. The constitutions were established by (H,H)‐, (H,C)‐ and NOE‐correlated NMR spectroscopy. In the reaction of 1 with 2a, in addition to 3 and 4, the methyl(propynyl)thioether complex [(CO)5Cr–S(Me)CCMe] (5) was formed. An isolable 3‐methylthio‐substituted cyclobutenylidene complex, [(CO)5CrPh2] (9) was obtained from [(CO)5CrCCPh2] (8) and 2a. The 4,5,6,7‐tetrahydroindenylthioether ligand of 11 was cleaved from the metal by exposure of 11 adsorbed on silica gel to air or by treatment of 11 with [NEt4]Br in dichloromethane.
Reactions of Complex Ligands, LXX. An Intramolecular Alkyne Insertion/Carbonylation/Cyclization Sequence of Chromium Aminocarbene Complexes: A Novel Access to Indole and Indenoindole Skeletons
Authors: Leese Thomas , Dötz Karl Heinz 
Published: July 2007

Abstract2‐Alkynylanilinocarbene chromium complexes 1–7 bearing a rigid arene C2 spacer between the aminocarbene and alkyne units were prepared from pentacarbonyl(aroyl)chromates(–I), acetyl bromide, and 2‐alkynylanilines. They undergo intramolecular cyclization the course of which depends on the substitution pattern at the alkyne terminus. A tandem alkyne insertion into the metal–carbene bond/carbonylation sequence affords Cr(CO)3‐coordinated 3‐indolylketenes 8, 9, 12–14 by using a bulky substituent; the rate of the reaction increases with N‐alkylation. Less bulky n‐alkynylanilinocarbene complexes 4, 5 exhibit two competing carbene annulation sequences: Benzannulation leads to benzo[a]carbazoles 15, 16, whereas cyclopentannulation without prior carbonylation furnishes indeno[1,2‐b]indoles 17, 18.
The Reaction of As4Sn (n = 3, 4) and As2S3 with (C5Me4R)2Co2(CO)2 (R = Me, Et): Fragmentation and Reassembling of Main‐Group Ligands by Organometallic Complexes
Authors: Brunner Henri , Kauermann Heike , Poll Ludwig , Nuber Bernhard , Wachter Joachim 
Published: July 2007

AbstractThe reaction of Cp2#Co2(CO)2 1 (Cp# = Cp* or Cpx; Cp* = C5Me5: a; Cpx = C5Me4Et: b) with equimolar amounts of As4Sn (n = 3, 4) and As2S3 was investigated at different temperatures. The formation of Cp2#Co2(CO)As2S2 3, Cp2#Co2As2S3 4, Cp3#Co3As2S4 5, and Cp3#Co3As4S2 6 was observed in ratios depending on the reaction conditions. Starting from As4S4 or As4S3 and 1b insertion of a CpxCo(CO) fragment into one of the As–As bonds of the cages was achieved in low yields leading to CpxCo(CO)As4S4 2b and CpxCo(CO)As4S3 8, respectively. Structures were studied by means of IR and 1H‐NMR spectroscopy and X‐ray diffraction analyses. Cp2#Co2(CO)As2S2 3 may be supposed to be the key intermediate in the whole reaction sequence: On heating solutions of 3 complexes 4–6 of higher nuclearity and different connectivity within the inorganic ligand were formed.
Hexacoordinated Group‐14 Elements with Phosphorus Donor Ligands: Syntheses and Structures of Cl2E[C(PMe2)2(SiMe3)]2 (E = Si, Ge, Sn)
Authors: Karsch Hans H. , Deubelly Brigitte , Keller Ursula , Steigelmann Oliver , Lachmann Joachim , Müller Gerhard 
Published: July 2007

AbstractThe group‐14 tetrahalides ECl4 (E = Si, Ge, Sn) react with two equivalents of Li[C(PMe2)2(SiMe3)] to give the trans‐hexacoordinated complexes Cl2E[C(PMe2)2(SiMe3)]2, which were characterized spectroscopically and by structure determinations in the solid state. The complexes were found to crystallize with or without tetrahydrofuran (THF) molecules, depending on the presence or absence of this solvent. In the case of the silicon complex, the structures of both crystal forms were determined, showing slightly different molecular structures of the complexes in the solid state. Without cocrystallized THF, Cl2Si[C(PMe2)2(SiMe3)]2 has no crystallographically imposed molecular symmetry, while in the presence of THF its crystallographic symmetry is C2h (2/m). The tin and germanium complexes were crystallized either with and without THF molecules, respectively, their crystal structures being isotypic with the respective ones of the silicon complex. In all cases, small amounts of the cis‐hexacoordinated isomers were also observed in solution, but only in the case of the silicon complex, it was isolated in pure form. It rearranges to the trans isomer at ambient temperature. trans‐Cl2Si[C(PMe2)3]3, trans‐Cl2Si[C(PPh2)2(SiMe3)]2 and cis‐Me2‐Si[C(PMe2)2(SiMe3)]2 were likewise obtained.