L. Zsolnai

Übergangsmetallkomplexe mit schwefelliganden: XIV. (NEt4)2[Cr(CO)3(S2C6H4)], bis-tetraethylammoniumtricarbonyl-1,2-benzendithiolatochromat(0), ein 16e-konfigurierter chrom(0)-komplex mit fünffach koordiniertem chrom; röntgenstrukturanalyse und reaktionen

Abstract According to the X-ray structure analysis (NEt 4 ) 2 [Cr(CO) 3 S 2 C 6 H 4 ] contains mononuclear anions, in which the chromium is coordinated by three CO ligands and two sulfur atoms of the 1,2-benzenedithiolate ligand forming a distorted trigonal bipyramid; thus [Cr(CO) 3 S 2 C 6 H 4 ] 2− represents a five-coordinate chromium(0) complex with formal 16 e configuration. Due to the coordinatively as well as electronically unsaturated chromium center [Cr(CO) 3 S 2 C 6 H 4 ] 2− is highly reactive; the 18 e complexes [Cr(CO) 4 S 2 C 6 H 4 ] 2− and [Cr(NO) 2 (S 2 C 6 H 4 ) 2 ] 2− are obtained on reactionwith CO and NO + or NO, respectively. The C 6 H 4 S 2 ligands in the latter complex can be alkylated by 1,2-C 2 H 4 Br 2 yielding [Cr(NO) 2 dttd] (dttd 2 = 2,3,8,9-dibenzo-1,4,7,10-tetrathiadecan(−2)); reaction of [Cr(NO) 2 (MeCN) 4 (PF 6 ) 2 with Na(CH 3 SC 6 H 4 S) gives the binuclear complex [Cr(NO)(CH 3 SC 6 H 4 S) 2 ] 2 .

Trigonal-planar koordiniertes Sn0 in [{Cp′(CO)2Mn} 2SnHal]−:Zinnverbindungen vom “Iniden”-Typ

Abstract The hydride complexes Na·([{L(CO)2Mn}2H]) (Na·1) (L = Cp, Cp′, Cp*), react with tin halides Sn(Hal)2 to give dimanganastannacumulene compounds [L(CO)2MnSnMn(CO)2L] (2. For L = Cp* the compound [Cp*(CO)2MnSnMn(CO)2Cp*] (2a, which is already known, can be isolated. For L = Cp, Cp′, 2 is only available in solution. In the presence of 2,2,2-Crypt. the cumulene intermediates 2 add the halide present in the solution forming the anionic “inidene” compounds Mn(CO)2L]− (4). For L = Cp′ the compounds 4 (Hal = Br (4a; Hal = Br (4b); Hal = (4c) are characterized by X-ray analyses. The compounds 4 show trigonal planar coordination around the bridging tin(0). Their geometry thus corresponds to the one observed at their isoelectronic neutral analogues with group 15 bridging elements (X = P, As, Sb, Bi). Synthesis and properties of the tin(0) complexes 4, as well as of tin(II) derivates of type [{L(CO)2Mn}Sn(SR)3]− (3 are presented and discussed with regard to spectroscopic and structural data.

Übergangsmetall-komplexe mit schwefelliganden: VII. Synthese und struktur der benzoldithiolato-eisen-komplexe [AsPh4]2[Fe(S2C6H4)2] und [Fe(S2C6H4)(PMe3)3]

Abstract Reaction of FeCl 2 · 4H 2 O with o -benzenedithiolate and AsPh 4 + gives the paramagnetic (μ eff 3.55 BM, 295 K) compound (AsPh 4 ) 2 [Fe(S 2 C 6 H 4 ) 2 ], whose structure consists of discrete tetrahedral AsPh 4 + cations and mononuclear planar [Fe(S 2 C 6 H 4 ) 2− anions forming a distorted antifluorite lattice. From the reaction mixture of FeCl 2 · 4H 2 O, o -benzenedithiolate and an excess of PMe 3 , the 16e diamagnetic [Fe(S 2 C 6 H 4 )(PMe 3 ) 3 ] could be isolated, which, in contrast to original expectations, contains pentacoordinate iron in a distorted square-pyramidal ligand sphere. [Fe(S 2 C 6 H 4 )(PMe 3 ) 3 ] looses PMe 3 on reaction with CO and yields [Fe(S 2 C 6 H 6 )(PMe 3 ) 2 (CO) 2 ]; applying equivalent amounts of CO the binuclear complex [Fe(S 2 C 6 H 4 )(PMe 3 ) 2 CO] 2 is formed.

Addition von Alkinen an die μ3-Brückenelemente von (μ3-X)2Fe3(CO)9 (X = Rp, Se, Te)☆

Abstract The compounds (μ 3 -X) 2 Fe 3 (CO) 9 (R = i Pr, t Bu) add alkynes (MeCCMe, PhCCH, PhCCPh) upon photochemical activation. In the resulting products (RPCR′=CR″ PR(Fe 3 (CO) 9 ( 2a–f ) the two phosphorous centres are bridged by the alkyne entity. The double bond in the bridging unit is coordinated side-on to one of the Fe(CO) 3 groups. The compounds (μ 3 -X) 2 Fe 3 (CO) 9 (X = Se, Te) add PhCCH upon thermal activation to yield (XCPh=CHX)Fe 2 (CO) 6 (X = Se: 4a , X = Te: 4b ). The syntheses and the properties of the compounds 2 and 4 are discussed. Their structures are illustrated by two examples, which were characterised by X-ray diffraction studies.

Neue methoden zur einführung von μ3-chalkogenbausteinen in carbonylmetallcluster; XCN− (X = S, Se, Te) und R′XXR′ (X = Se, Te) als selektive reagenzien

Abstract The RP-bridged clusters Fe3(CO)10(μ3-RP) (1) (A) when treated with XCN− (X = S, Se, Te) yield the anionic addition products (D). Reaction of these adducts with Et3OBF4 leads to the high yield formation (90%) of Fe3(CO)9(μ3-RP)(μ3-X) (2). The compounds 2 are also obtained from 1 and R′XXR′ (X = Se, Te), albeit less selectively (≈ 60%). In addition the binuclear species Fe2(CO)6(μ2-R′X)(μ2-RPXR′) (3) are obtained (≈ 30%). In the case of R′TeTeR′ Fe3(CO)8(μ3-RP)(μ2-R′Te)2 (4) is formed as an additional product. The structures of the compounds 2, 3 and 4 are documented by X-ray analysis. The geometry of 2 is analysed in terms of a metallaheterocyclobutadiene model, η4-[F R]Fe(CO)3, in comparison with known structural analogues. NMR data (1H, 13C, 31P, 77Se, 125Te) are reported for all new compounds.

Synthese funktionalisierter tipod-Liganden: Aufbau, Veresterung und Koordinationsfähigkeit von HOCH2C (CH2PPh2)3

Abstract Starting from pentaerythritol, HOCH 2 C(CH 2 OH) 3 , the synthesis of the hydroxy functionalized tripod - ligand HOCH 2 C(CH 2 PPh 2 ) 3 , 4 , is achieved in a few steps. Esterification of the hydroxy group of 4 opens a route to the convergent construction of functionalized tripod -ligands R′COOCH 2 C(CH 2 PR 2 ) 3 . For ligand 4 and for its benzoyl derivative PhCOOCH 2 C(CH 2 PPh 2 ) 3 , 6 , the capability of forming facially coordinated tripod -complexes is verified by the formation of molybdenum and cobalt complexes. The results are documented by the usual analytical techniques as well as by X-ray analyses.

Ein neuer Zugang zu Arsinidenkomplexen aus Dimetallaarsacumulenium-Ionen

Abstract The dimetallaarsacumuleniumion [Cp′(CO)2MnAsMn(CO)2Cp′]+, 2, which is easily obtained by halide abstraction from the arsinidine complex , 1a, reacts with nucleophiles X− to give the arsinidene species , 1c–1f (1c: X = I, 1d: X = NCO, 1e: X = NCS, 1f: X = N3); with BH−4 as the nucleophile the parent compound , 1b, is obtained. The new arsinidene compounds 1b–1f are characterized by the standard analytic and spectroscopic techniques; in addition X-ray analyses are reported for 1b, 1c and 1e.

Umwandlung von carbonylgruppen an Fe3(CO)10(μ3-PR) in carben-, carbin- und alkinbausteine

Abstract The cluster Fe3(CO)10(μ3-PR) (1) is transformed into carbene-functionalised clusters 2 and 3 under the conditions of Fischer-type carbene syntheses. The compounds 3 contain a terminal carbene ligand R′COR″, whereas the carbene ligand in 2 coordinates to two metal atoms via the carbene carbon atom, and to the third iron centre through the oxygen of the R″O substituent. Irradiation of compounds 2 initiates migration of the alkoxy group from the carbene carbon atom to phosphorus. This results in a (μ2-RPOR″) and a (μ3-R′C) group being present in 4. Whereas these high yield reactions are conceptionally simple, the formation of minor byproducts 4b, 5 and 6 shows that, under the reaction conditions applied, the reduction of carbonyl groups to R″C and R″OC cluster constituents occurs. Compounds 5 and 6 are members of a well characterised family of clusters, generally derived from 1 by its reaction with alkynes. Compound 5 contains R′CCOR″ as the alkyne fragment, whereas in the pentagonal bipyramidal cage 6 the alkyne constituent is R″OCCOR″. The π-donor properties of the ethoxy groups in 6 lead to a characteristic distortion of the closo-geometry generally observed for compounds of this type. All compounds have been characterised by the usual analytical and spectroscopic techniques as well as by X-ray diffraction studies for at least one member of each group of compounds.

Heterocumulene mit MetallArsen- bzw. MetallAntimon-Mehrfachbindung

Abstract The chloroarsinidene compound , 1a (Cp′ = η5-C5H4CH3) upon reaction with GaCl3 transforms into the tetrachlorogallate of the dimanganaarsacumuleniumion [Cp′(CO)2MnAsMn(CO)2Cp′]+, 2a. The cumulene type bonding in 2a is evidenced by the spectroscopic and structural (X-ray analysis of 2a·GaCl4−) properties. The chloroarsinidene compound , 1b, and the chlorostibinidene complex , 1c, (Cp* = η5-C5(CH3)5) are correspondingly transformed into dimetallaarsa- ([(CO)5CrAsCr(CO)5]+, 2b) and dimetallastiba- ([Cp*(CO)2MnSbMn(CO)2Cp*]+, 2c) cumuleniumions respectively. The cations 2b, 2c are unequivocally characterized by spectroscopic techniques; however, crystal structure analyses could not yet be obtained. Under similar conditions the chlorostibinidene compound , 1d, gives the trinuclear cation [Cp′(CO)2 Mn]Cp′(CO) 2 MnSb Mn(CO)2Cp′+, 4, which, as shown by X-ray analysis of 4·CF3SO3−, contains a trigonally planar coordinated Sb+-cation.

{η6-aren(CO)2Cr} als metallorganische 16-Elektronenkomplexfragmente: Synthese und Eigenschaften von Stibinidenkomplexen [{η6 -are

Abstract Transition metal complexes with doubly bridging antimony(I) halide ligands, [{η 6 -arene(CO) 2 Cr}2 SbX] ( 1-4 ) have been synthesized