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p-Fluorophenylisocyanide (CNPhpF) reacts with [Re(CO)5Br] under stepwise exchange of the carbonyl ligands depending on the conditions applied. The reaction stops with the formation of fac-[Re(CO)3Br(CNPhpF)2] in boiling THF. An ongoing carbonyl exchange is observed at higher temperatures, e. g. in refluxing toluene, with the final formation of the [Re(CNPhpF)6]+ cation. The progress of the reactions has been studied by 19F NMR spectroscopy and the structures of [Re(CO)Br(CNPhpF)4] and [Re(CNPhpF)6](BPh4) have been elucidated by X-ray diffraction.

Two potentially tripodal ligands, tris(1-phenyl-1H-1,2,3-triazol-4-yl)phosphine oxide (OP((1,2,3)Tz(1-Ph))(3)) and tris(1-benzyl-1H-1,2,3-triazol-4-yl)phosphine oxide (OP((1,2,3)Tz(1-benz))(3)), were used in reactions with [Re(CO)(5)Br] and (NEt4)(2)[Tc(CO)(3)Cl-3]. While the formation of rhenium complexes with bidentate and tridentate coordinated phosphine oxides was observed, for technetium only cationic complexes with tripodal coordinated OP((1,2,3)Tz(1-R)) ligands were isolated. The products have been characterized spectroscopically and by single crystal X-ray diffraction.

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The deep blue, paramagnetic Cs2[TcII(NO)F5] is formed during reactions of pertechnetate, acetohydroxamic acid, and CsF in aqueous HF. A reaction of Cs2[Tc(NO)F5] with BF3·MeOH in acetonitrile gives yellow blocks of the fluorido-bridged dimer [{TcI(NO)(CH3CN)4}2F](BF4)3. The compound is stable as solid and in acetonitrile solutions. The complex cation contains a bent μ-F– ligand and two linear nitrosyl groups.

A novel propargyl-substituted thiocarbamoylbenzamidine has been synthesized. The compound acts as a tetradentate ligand and forms stable complexes with the {ReVO}3+ and {TcVO}3+ cores. 'Click' couplings of the resulting complexes with benzyl azide lead to prototype triazole derivatives, which were analyzed by NMR, IR, and mass spectrometry as well as by X-ray diffraction. A similar coupling procedure has been applied for an azido-modified angiotensin-II peptide, which gives the desired rhenium(V) bioconjucate with good yields. The ease of this coupling and the stability of the conjugate recommends such tetradentate thiocarbamoylbenzamidines also for clinically relevant bioconjugates with 99mTc.

Reactions of (NEt4)2[Re(CO)3Br3] with N-heterocyclic thiols such as 2-mercaptobenzimidazole (H2Sbenzim), 2-mercaptothiazoline (HSthiaz), or 5-mercapto-1-methyltetrazole (HSmetetraz) give rhenium(I) complexes of various compositions: (NEt4)[Re(CO)3Br2(H2Sbenzim)], [Re(CO)3(HSthiaz)3]Br, and (NEt4)[Re2(CO)6(μ-S-Smetetraz-κS)(μ-N,S-Smetetraz-κS,N)2]. Corresponding reactions with 2-mercaptopyridine (HSpy) and bis(2-pyridine)diselenide [(Sepy)2] did not give defined products in reasonable yields, whereas [Re(CO)5Br] reacts with HSpy and (Sepy)2 with formation of [Re(CO)3(HSpy)3]Br and [Re2(CO)6(Sepy)2], respectively. All reactions were performed without the addition of a supporting base and the sulfur-containing organic ligands are coordinated in their thione forms with the exception of Smetetraz– in its μS-bridging coordination mode in (NEt4)[Re2(CO)6(μ-S-Smetetraz-κS)(μ-N,S-Smetetraz-κS,N)2], which can be regarded as thiolate. The bonding mode of the selenium containing ligands in the dimeric compound [Re2(CO)6(Sepy)2] (C–Se distance: 1.93 A) can also best be described as selenolate. The products are stable on air at an ambient temperature. They were studied spectroscopically and by X-ray diffraction.

N-[3-(Phenyltellanyl)propyl]picolinamide (HL1) or N-[N″,N″-methyl(phenyl)aminothiocarbonyl]-N′-[3-(phenyltellanyl)propyl]benzamidine (HL2) react with equivalent amounts of PtCl2 or PdCl2 with formation of neutral [MCl(L1-κN,N′,Te)] or [MCl(L2-κS,N,Te)] chelates. A corresponding reaction of HL2 with HgCl2 results in the formation of [HgCl2(HL2-κS,Te)]. Treatment of [PtCl(L1-N,N′,Te)] with elemental iodine results in the exclusive oxidation of the metal ion and the platinum(IV) complex [PtI3(L1-κN,N′,Te)] could be isolated in reasonable amounts. A decomposition of the tellurium-containing ligand and the formation of [PdI2(PhTeI)2] was observed during a similar procedure with the corresponding palladium complex. The bonding situation inside the latter compound was analyzed through density functional theory calculations.

Oxidorhenium(V) complexes with N,N-dialkyl-N′-benzoylselenoureas (HL) were prepared from reactions with (NBu4)[ReOCl4]. The formation of compounds such as [ReO(L-κO,Se)2(OMe)] or [{ReO(L-κO,Se)2}2O] suggests parallels with the established chemistry of corresponding benzoylthioureas, while the isolation of unusual species such as [ReO(L-κO,Se)2(L-κSe)], [{ReO(L-κO,Se)2}2Se3] and the formation of the respective diselenide suggest a more complicated reaction pathway with the unstable selenium compounds, and one in which degradation products of the ligands also plays a role.

Potassium hexafluoridotechnetate(IV), K2[TcF6], slowly reacts in aqueous solution with acetohydroxamic acid with formation of the ammine nitrosyltechnetium(I) complex [Tc(NO)(NH3)4F]+. The product crystallizes as mixed TcF62–/HF2– salt of the composition [Tc(NO)(NH3)4F]4[TcF6][HF2]2. [Tc(NO)(NH3)4F]+ represents the first nitrosyltechnetium complex with a fluorido ligand in its coordination sphere. The Tc–F bonds in two crystallographically independent species are 1.987(2) and 2.034(2) A, respectively. This is slightly longer than in the [TcF6]2– counterion.

[MOCl4]– complexes (M = Re, Tc) react with thianes derived from N-[(diethylamino)(thiocarbonyl)]benzamidoyl chloride and 2-mercaptophenol (HL1) and 2-mercaptoaniline (HL2) under C–S bond cleavage and formation of oxorhenium(V) and oxotechnetium(V) complexes with the resulting decomposition products 2-mercaptophenol and N-[(dialkylamino)thiocarbonyl]-N′-2-mercaptophenyl)benzamidine (H2L2a), respectively. The products, (NBu4)[ReO(S,O-C6H4)2], [ReOCl(L2a)] and [TcO(L2a)] were obtained in good yields and isolated in crystalline form. Single-crystal X-ray studies reveal square-pyramidal coordination environments with apical oxo ligands for all three product complexes under study.

Unsupported cobalt sulfide-molybdenum sulfide mixed catalysts exhibit two distinct E. S. R. signals. A first signal (g= 2.007, ΔH=90G) is detected at room temperature. It is attributed to Mo5+. The Mo5+ content decreases with increasing Co content, from a value Mo5+/Mo of 0.01% with pure molybdenum sulfide, to negligible values for Co/(Co + No) > 0.5. A second, low temperature, signal gradually appears between 143 and 133°K (g = 2.17, ΔH = 300-600G). It is apparently related to some cobalt containing species. This signal, practically negligible for each monometallic sulfide, exhibits a sharp maximum for a value Co(Co + Mo) of 0.2, which corresponds to maximal intrinsic (per m2) catalytic activities of the samples in the hydrogenolysis of thiophene, hydrogenation of cyclohexene and isomerization of cyclohexane.

Tricarbonylrhenium(I) and -technetium(I) halide (halide = Cl and Br) complexes of ligands derived from 4,5-diazafluoren-9-one (df) and 1,10-phenanthroline-5,6-dione (phen) derivatives of benzoic and 2-hydroxybenzoic acid hydrazides have been prepared. The complexes have been characterized by elemental analysis, MS, IR, 1 H NMR and absorption and emission UV/Vis spectroscopic methods. The metal centres (Re I and Tc I ) are coordinated through the nitrogen imine atoms and establish five-membered chelate rings, whereas the hydrazone groups stand uncoordinated. The 1 H NMR spectra suggest the same behaviour in solution on the basis of only marginal variations in the chemical shifts of the hydrazine protons.

[NEt4]2[Re(CO)3Br3] and [NEt4]2[Tc(CO)3Cl3] react with trimethylsilyltriphenylphosphoraneimine, Me3SiNPPh3, under exchange of the bromo ligands and the formation of cationic [M(CO)3(HNPPh3)3]+ complexes (M = Re, Tc). The required protons are abstracted from the solvent CH2Cl2. The steric bulk of the organic ligands causes a marked distortion of the established coordination polyhedra from an idealized octahedron with bond angles between neighbouring donor atoms between 81.81(8)° and 96.66(8)°. The reaction of [NEt4]2[Re(CO)3Br3] with Me3SiNP(Ph2)CH2PPh2 in CH2Cl2 yields the neutral complex [Re(CO)3Br{HNP(Ph2)CH2PPh2)], which contains a neutral, chelate-bonded (diphenylphosphinomethyl)diphenylphosphoraneimine ligand. A similar reaction with the bifunctional phosphoraneimine Me3SiNP(Ph2)CH2(Ph2)PNSiMe3 gives only small amounts of a binuclear rhenium(I) complex of the composition [{Re(CO)3Br2}2(HNP(Ph2)CH2(Ph2)PNH)]2-, whereas the major amount of the bis-phosphoraneimine undergoes an intramolecular rearrangement to yield [H2NP(Ph2)NP(Ph2)CH3]Br. An X-ray structure analysis shows a widespread delocalization of electron density over the central part of the cation. Rhenium(I)- und Technetium(I)-Tricarbonylkomplexe mit Phosphoranimin-Liganden Reaktionen von [NEt4]2[Re(CO)3Br3] oder [NEt4]2[Tc(CO)3Cl3] mit Trimethylsilyltriphenylphosphoranimin, Me3SiNPPh3, verlaufen unter Austausch der Bromoliganden und der Bildung kationischer [M(CO)3(HNPPh3)3]+-Komplexe (M = Re, Tc). Die Protonierung der organischen Liganden erfolgt als Folge einer Zersetzung des Losungsmittels CH2Cl2. Die Koordination dreier sterisch anspruchsvoller HNPPh3-Liganden fuhrt zu einer deutlichen Verzerrung der oktaedrischen Koordinationsspharen der Metallatome und Bindungswinkeln zwischen 81.81(8)° and 96.66(8)° zwischen benachbarten Donoratomen. Mit dem potentiell zweizahnigen Liganden Me3SiNP(Ph2)CH2PPh2 reagiert [NEt4]2[Re(CO)3Br3] in CH2Cl2 unter Bildung des Neutralkomplexes [Re(CO)3Br{HNP(Ph2)CH2PPh2}]. Dagegen liefert eine analoge Reaktion mit dem bifunktionellen Phosphoranimin Me3SiNP(Ph2)CH2(Ph2)PNSiMe3 nur in geringen Ausbeuten einen zweikernigen, anionischen Rhenium(I)-Komplex der Zusammensetzung [{Re(CO)3Br2}2(HNP(Ph2)CH2(Ph2)PNH)]2-, wahrend als Hauptprodukt einer intramolekularen Umlagerung das Salz [H2NP(Ph2)NP(Ph2)CH3]Br entsteht. Eine Kristallstrukturanalyse dieser Verbindung belegt eine weitreichende Delokalisierung von Elektronendichte im zentralen Teil des Kations.

Mono-, di or trinuclear dioxouranium complexes with benzoylhydrazonato or azomethine ligands were prepared by reactions of common dioxouranium precursors such as UO2(NO3)2 · 6 H2O or [NBu4]2[UO2Cl4] with vanillin benzoylhydrazone (H2L4), salicylaldehyde benzoylhydrazone (H2L5), 2-hydroxyacetylbenzene salicylhydrazone (H3L6) or N-(2-ethoxycarbonyl-3-oxo-but-1-en(1)yl)-2-aminophenol (H2L7). Spectroscopic and X-ray crystallographic studies on the complexes [NBu4]2[UO2Cl4] · 2 H2L4, [UO2(HL5)(H2L5)2](NO3), [HNEt3]2[{UO2(L6)}2] and [HNEt3]2[{UO2(L7}3O] confirm that the individual donor atom constellation, the size of the potential chelate rings and the acidity of the OH and NH functionalities of the proligands have a strong influence on the structure of the products. Ein-, zwei- und dreikernige Dioxouranium(VI)-Komplexe mit Hydrazonat- und Azomethin-Liganden Ein-, zwei oder dreikernige Dioxouranium(VI)-Komplexe entstehen bei der Umsetzung einfacher Uranylverbindungen wie UO2(NO3)2 · 6 H2O oder [NBu4]2[UO2Cl4] mit Vanillinbenzoylhydrazon (H2L4), Salicylaldehydbenzoylhydrazon (H2L5), 2-Hydroxyacetylbenzensalicylhydrazon (H3L6) oder N-(2-ethoxycarbonyl-3-oxo-but-1-en(1)yl)-2-aminophenol (H2L7). Spektroskopische und kristallographische Untersuchungen an den Komplexen [NBu4]2[UO2Cl4] · 2 H2L4, [UO2(HL5)(H2L5)2](NO3), [HEt3N]2[{UO2(L6)}2] und [HEt3N]2[{UO2(L7}3O] zeigen, dass die individuelle Donoratomkonstellation in den Liganden, die Grose der potentiellen Chelatringe und die Aciditat der OH- und NH- Gruppierungen in den Proliganden einen starken Einfluss auf die Struktur der Metallkomplexe haben.

Acetylpyridine benzoylhydrazone and related ligands react with common dioxouranium(VI) compounds such as uranyl nitrate or [NBu4]2[UO2Cl4] to form air-stable complexes. Reactions with 2, 6-diacetylpyridinebis(benzoylhydrazone) (H2L1a) or 2, 6-diacetylpyridinebis(salicylhydrazone) (H2L1b) give yellow products of the composition [UO2(L1)]. The neutral compounds contain doubly deprotonated ligands and possess a distorted pentagonal-bipyramidal structure. The hydroxo groups of the salicylhydrazonato ligand do not contribute to the complexation of the metal. The equatorial coordination spheres of the complexes can be extended by the addition of a monodentate ligand such as pyridine or DMSO. The uranium atoms in the resulting deep-red complexes have hexagonal-bipyramidal coordination environments with the oxo ligands in axial positions. The sterical strains inside the hexagonal plane can be reduced when two tridentate benzoylhydrazonato ligands are used instead of the pentadentate 2, 6-diacetylpyridine derivatives. Acetylpyridine benzoylhydrazone (HL2) and bis(2-pyridyl)ketone benzoylhydrazone (HL3) deprotonate and form neutral, red [UO2(L)2] complexes. The equatorial coordination spheres of these complexes are puckered hexagons. X-ray diffraction studies on [UO2(L1a)(pyridine)], [UO2(L1b)(DMSO)], [UO2(L2)2] and [UO2(L3)2] show relatively short U—O bonds to the benzoylic oxygen atoms between 2.328(6) and 2.389(8) A. This suggests a preference of these donor sites of the ligands over their imino and amine functionalities (U—N bond lengths: 2.588(7)—2.701(6) A ). Dioxouranium-Komplexe mit Acetylpyridinbenzoylhydrazon und verwandten Liganden Acetylpyridinbenzoylhydrazon und davon abgeleitete Liganden reagieren mit Uranylnitrat oder [NBu4]2[UO2Cl4] unter Bildung luftstabiler Dioxouranium(VI)-Komplexe. Bei Reaktionen mit 2, 6-Diacetylpyridinbis(benzoylhydrazon) (H2L1a) und 2, 6-Diacetylpyridinbis(salicylhydrazon) (H2L1b) entstehen gelbe Pulver der Zusammensetzung [UO2(L1)]. Die Koordination des Uranatoms in den Neutralkomplexen mit doppelt deprotonierten organischen Liganden ist verzerrt pentagonal-bipyramidal. Die Hydroxosubstituenten des Salicylhydrazonato-Liganden [L1b]2— sind an der Komplexierung des Metallatoms nicht beteiligt. Reaktionen von [UO2(L1)]-Komplexen mit monodentaten Liganden wie Pyridin oder DMSO fuhren zur Aufweitung der aquatorialen Koordinationssphare und zur Bildung von tiefroten, kristallinen Verbindungen mit einer verzerrten, hexagonal-bipyramidalen Koordination um die Uranatome. Die sterische Belastung der aquatorialen Koordinationsebene kann verringert werden, wenn anstelle der funfzahnigen H2L1-Liganden dreizahnige Benzoylhydrazonato-Liganden verwendet werden. 2-Acetylpyridinbenzoylhydrazon (HL2) und Bis(2-pyridyl)ketonbenzoylhydrazon (HL3) bilden unter einfacher Deprotonierung neutrale Komplexe der Zusammensetzung [UO2(L)2]. Die hexagonalen Grundflachen der gebildeten Bipyramiden sind in diesen Produkten deutlich gewellt. Kristallstrukturanalysen von [UO2(L1a)(Pyridin)], [UO2(L1b)(DMSO)], [UO2(L2)2] und [UO2(L3)2] zeigen relativ kurze Bindungen zwischen den Uranatomen und den Benzoylgruppierungen (2.328(6)—2.389(8) A). Das legt eine bevorzugte Bindung an die Sauerstoffatome der Liganden nahe, wahrend die UranStickstoff-Bindungen deutlich langer sind (2.588(7)—2.701(6) A).

Terminal ‘N3—’ ligands in rhenium and technetium nitrido complexes are sufficiently nucleophilic to react with Lewis acids under formation of nitrido-bridged compounds. The reactivity of the nucleophilic centre and the nature of the formed compounds are strongly dependent on the Lewis acid and the composition of the metal complex used. Air-stable compounds with Re≡N-ER3 bridges are formed when ER3 is BR3 (R = H, Cl, Br, Ethyl, Phenyl, C6F5), BCl2Ph, GaCl3, CPh3+, or PPh3. The six-co-ordinate rhenium(V) complexes [ReNX2(PMe2Ph)3] (X = Cl, Br), [ReN(X)(Et2dtc)(PMe2Ph)2] (Et2dtc— = diethyldithiocarbamate) and [ReN(Et2dtc)2(PMe2Ph)] have been proved to be excellent starting materials for this type of reactions, whereas the five-co-ordinate precursors [ReNCl2(PPh3)2], [ReN(Et2dtc)2], [ReN{Ph2P(S)NP(S)Ph2}2] or [ReNCl4]— only react with the most reactive Lewis bases of the examples mentioned above such as BCl2Ph or B(C6F5)3. The rhenium-nitrido bond lengths remain almost unchanged by the adduct formation, whereas a significant decrease of the trans-influence of the nitrido complexes has been observed as can be seen by a shortening of the corresponding bond lengths or dimerization of five-co-ordinate precursors. Electrophilic attack of the Lewis acid to a donor atom of the equatorial co-ordination sphere of the rhenium complex results in the formation of ‘underco-ordinate’ metal centres which resemble to di-, tri or tetrameric units with asymmetric nitrido bridges between each two rhenium atoms. EPR spectroscopy is an excellent tool to reflect the formation of nitrido bridges at the paramagnetic (d1) [ReNX4]— core (X = F, Cl, Br, NCS). The spectral parameters derived for the products of reactions of [ReNCl4]— with various boron compounds indicate an increase of the covalency of the equatorial Re-L bonds as a consequence of the formation of a nitrido bridge. The tendency for the formation of nitrido bridges with Lewis acids is significantly lower for technetium compounds compared to their rhenium analogues. Only a few examples with BH3 and BPhCl2 have been established. Reaktionen von Rhenium- und Technetium-Nitridokomplexen mit ER3 Fragmenten (E = B, Ga, Al, C, P; R = H, Alkyl, Aryl) — Eine Ubersicht Der “N3—”-Ligand in Rhenium- und Technetiumkomplexen mit terminalen Nitridofunktionen ist ausreichend nukleophil, um mit Lewis-Sauren zu nitridoverbruckten Verbindungen zu reagieren. Die Zusammensetzung der Produkte ist sowohl von der verwendeten Lewis-Saure als auch von der Struktur des Rheniumkomplexes abhangig. Luftstabile Verbindungen mit Re≡N-ER3-Brucken entstehen mit ER3 = BX3 (X = Cl, Br, H, Ethyl, Phenyl, C6F5), BCl2Ph, GaCl3, CPh3+ oder PPh3. Als besonders geeignete Startverbindungen erwiesen sich die sechsfach koordinierten Rhenium(V)-Komplexe [ReNX2(PMe2Ph)3] (X = Cl, Br), [ReN(X)(Et2dtc)(PMe2Ph)2] (Et2dtc— = N, N-Diethyldithiocarbamat) und [ReN(Et2dtc)2(PMe2Ph)]. Rheniumkomplexe mit der Koordinationszahl 5 wie [ReNCl2(PPh3)2], [ReN(Et2dtc)2], [ReN{Ph2P(S)NP(S)Ph2}2] oder [ReNCl4]— reagieren dagegen nur mit den reaktivsten der oben angefuhrten Lewis-Sauren: BCl2Ph oder B(C6F5)3. Die Lange der Rhenium-Stickstoff-Mehrfachbindung bleibt von der Ausbildung der Nitridobrucke weitgehend unberuhrt, wahrend eine drastische Abnahme des trans-Einflusses der Nitridoliganden zu verzeichnen ist. Das wird an der Verkurzung der Bindungen zu den trans-standigen Donoratomen in den Komplexen mit der Koordinationszahl 6 sowie an der Dimerisierung eines funffach koordinierten Rhenium(V)-Komplexes infolge der Ausbildung einer Nitridobrucke sichtbar. Ein elektrophiler Angriff von Lewis-Sauren an den Donoratomen der aquatorialen Koordinationssphare fuhrt zur Abspaltung einzelner Liganden und zur Ausbildung “unterkoordinierter” Metallatome, die sich durch Zusammenlagerung zu di-, tri- oder tetrameren Einheiten mit asymmetrischen Nitridobrucken zwischen jeweils zwei Rheniumatomen stabilisieren. Die EPR-Spektroskopie erwies sich als eine geeignete Methode zur Untersuchung von Reaktionen, die zur Bildung von Nitridobrucken ausgehend von Komplexen des Typs [ReNCl4]— (X = F, Cl, Br, NCS) fuhren. Die Tendenz zur Ausbildung von Nitridobrucken mit Lewis-Sauren ist beim Technetium viel schwacher ausgepragt als beim Rhenium. Es existieren nur wenige Beispiele solcher Verbindungen mit BH3 und BCl2Ph.

Novel rhenium(I) tricarbonyl complexes have been prepared by reactions of (Et4N)2[Re(CO)3Br3] with acetylpyridine benzoylhydrazone, Hapbhyd, di(2-pyridyl)ketone benzoylhydrazone, Hpy2bhyd, bis(2-pyridine)ketone, py2CO, and pyridinealdehyde terephtalaldehydebishydrazone, pytehyd. The ligands remain protonated when no supporting base is added and the following complexes have been isolated: [Re(CO)3Br(Hapbhyd)], [Re(CO)3Br(Hpy2bhyd-py, hyd)], [Re(CO)3Br(Hpy2bhyd-py1, py2)], [Re(CO)3Br(py2CO-N, N)] and [Re(CO)3Br(pytehyd)]. Addition of triethyl amine results in deprotonation of Hapbhyd and the formation of [Re(CO)3(OH2)(apbhyd)], whereas Hpy2bhyd is hydrolysed and a rhenium complex with the monoanionic bis(2-pyridyl)hydroxymethanolato ligand, {py2C(OH)O}-, is formed. The same compound, [Re(CO)3{py2C(OH)O}], is obtained when triethyl amine and water are added to a mixture of (Et4N)2[Re(CO)3Br3] and py2CO. The air-stable products have been studied by spectroscopic methods and X-ray crystallography. Tricarbonylkomplexe von Rhenium(I) mit Acetylpyridinbenzoylhydrazon und verwandten Liganden Durch Reaktionen von (Et4N)2[Re(CO)3Br3] mit Acetylpyridinbenzoylhydrazon, Hapbhyd, Di(2-pyridyl)ketonbenzoylhydrazon, Hpy2bhyd, Bis(2-pyridyl)keton, py2CO, und Pyridinaldehydterephtalaldehydbishydrazon, pytehyd, wurden neue Rhenium(I)-Tricarbonylkomplexe hergestellt und charakterisiert. Ohne Zugabe von Hilfsbasen koordinieren die Hydrazone als Neutralliganden und es konnten folgende Produkte isoliert werden: [Re(CO)3Br(Hapbhyd)], [Re(CO)3Br(Hpy2bhyd-py, hyd)], [Re(CO)3Br(Hpy2bhyd-py1, py2)], [Re(CO)3Br(py2CO-N, N)] und [Re(CO)3Br(pytehyd)]. Durch die Zugabe von Triethylamin erfolgt eine Deprotonierung von Hapbhyd, was zur Bildung von [Re(CO)3(OH2)(apbhyd)] fuhrt. Eine analoge Reaktion mit Hpy2bhyd fuhrt zur Hydrolyse des Proliganden und es entsteht ein Rheniumkomplex mit dem monoanionischen Bis(2-pyridyl)hydroxymethanolato-Liganden, {py2C(OH)O}—. Die gleiche Verbindung, [Re(CO)3{py2C(OH)O}], entsteht nach Zugabe von Triethylamin und Wasser zu einer Mischung aus (Et4N)2[Re(CO)3Br3] und py2CO. Die luftstabilen Produkte wurden mit spektroskopischen Methoden und durch Rontgenkristallstrukturanalysen untersucht.

[ReN(Et2dtc)2(Me2PhP)] (Me2PhP = Dimethylphenylphosphan, Et2dtc- = Diethyldithiocarbamat) reagiert mit SbCl3 in Dichloromethan unter Bildung von [{ReN-(Me2PhP)(Et2dtc)Cl}2{ReN(Et2dtc)2}2{SbCl3}2]. In dieser Verbindung wird ein {Re≡N-}4-Ring mit asymmetrischen Nitridobrukken durch die zusatzliche Koordination von SbCl3 an die Chloroliganden und Schwefelatome der Dithiocarbamatliganden stabilisiert. Der Mehrkernkomplex zersetzt sich beim Erhitzen in Acetonitril und aus den gebildeten Fragmenten entstehen der wiederum nitridoverbruckte Komplex [ReN(Me2PhP)(Et2dtc)Cl]4 und [Re-N(Et2dtc)2]. Die mehrkernigen Rheniumverbindungen wurden mit Hilfe der Kristallstrukturanalyse untersucht. Wahrend das 8-gliedrige {Re≡N-}4-Ringsystem in [{ReN(Me2PhP)(Et2dtc)Cl}2{ReN-(Et2dtc)2}2{SbCl3}2] nahezu planar ist, ist das in [ReN(Me2Ph-P)(Et2dtc)Cl]4 deutlich verzerrt und zeigt bei einem Blick entlang der diagonal zueinander angeordneten Rheniumatome V-Form mit einem Diederwinkel von 47, 88(2)° zwischen den beteiligten Flachen. [{ReN(Me2PhP)(Et2dtc)Cl}2{ReN(Et2dtc)2}2{SbCl3}2] — a Novel Tetranuclear Rhenium Complex with Asymmetric Nitrido Bridges The reaction of [ReN(Et2dtc)2(Me22hP)] (Me2PhP = dimethylphenylphosphine, Et2dtc- = diethyldithiocarbamate) with SbCl3 in dichloromethane results in the formation of [{ReN(Me2PhP)(Et22tc)Cl}2{ReN(Et2dtc)2}2{SbCl3}2]. A {Re≡N-}4 ring with asymmetric nitrido bridges is stabilised by the co-ordination of SbCl3 onto the chloro ligands and sulphur atoms of the dithiocarbamates. The compound decomposes upon heating in acetonitrile and the fragments of the tetrameric complex re-arrange to form [ReN-(Me2PhP)(Et2dtc)Cl]4 and [ReN(Et2dtc)2]. The multinuclear rhenium compounds have been studied by X-ray crystallography. The 8-membered {Re≡N-}4 ring system in [{ReN(Me2PhP)(Et2dtc)Cl}22ReN(Et2dtc)2}2{SbCl3}2] is almost planar, while that of [ReN(Me2PhP)(Et2dtc)Cl]4 is clearly V-shaped when viewed down either diagonal Re…Re axis. A dihedral angle of 47.88(2)° has been found between the contributing planes.

Die Reaktion von ReNCl2(PMe2Ph)3 mit NbCl5 in Toluol ergibt die Dreikernkomplexe [(Me2PhP)3Cl2Re≡N]2NbCl4 (1) und [Re3N3Cl5(PMe2Ph)6][NbCl6] (2). 1 bildet trikline Kristalle der Zusammensetzung 1 · 2 C7H8 (P 1; a = 1074,5(1); b = 1289,1(2); c = 1299,3(2) pm; α = 85,25(2)°; β = 81,04(2)°; γ = 86,02(1)°; Z = 1). In der zentrosymmetrischen Verbindung 1 koordinieren zwei Komplexe ReNCl2(PMe2Ph)3 mit ihren Nitridoliganden eine zentrale, quadratisch-planare Baugruppe NbCl4 unter Ausbildung einer gestreckten Anordnung Re≡N–Nb–N≡Re. Die Lange der Re–N-Dreifachbindungen betragt 172,2 pm. Die Nb–N-Abstande entsprechen mit 216,0 pm koordinativen Einfachbindungen. 2 bildet orthorhombische Kristalle mit der Raumgruppe P212121 und a = 1286,0(1); b = 2109,2(4); c = 2436,2(3) pm; Z = 4. Die drei Rheniumatome sind an den Ecken eines Dreiecks angeordnet und uber zwei asymmetrische Nitridobrucken und zwei ebenfalls asymmetrische Chlorbrucken verknupft. Die schwach abgewinkelten Nitridobrucken (Re–N–Re = 152° und 157°) sind durch Abstande Re–N von 169 und 207 pm bzw. 171 und 207 pm charakterisiert. Re1 bindet auserdem einen terminalen Nitridoliganden mit einem Abstand Re1–N1 = 166 pm. Synthesis and Structure of [(Me2PhP)3Cl2ReN]2NbCl4 and [Re3N3Cl5(PMe2Ph)6][NbCl6] The reaction of ReNCl2(PMe2Ph)3 with NbCl5 in toluene yields the trinuclear complexes [(Me2PhP)3Cl2ReN]2- NbCl4(1) and [Re3N3Cl5(PMe2Ph)6][NbCl6] (2). 1 forms triclinic crystals with the composition 1 · 2 C7H8 (P 1, a = 1074.5(1), b = 1289.1(2), c = 1299.3(2) pm, α = 85.25(2)°, β = 81.04(2)°, γ = 86.02(1)°, Z = 1). In the centrosymmetric compound 1 two complexes ReNCl2(PMe2Ph)3 coordinate with their nitrido ligands a square planar, central unit NbCl4 to form an almost linear arrangement Re≡N–Nb–N≡Re. The length of the Re–N triple bonds is 172,2 pm, and the Nb–N distances of 216.0 pm correspond to coordinative single bonds. 2 forms orthorhombic crystals with the space group P212121 and a = 1286.0(1), b = 2109.2(4), c = 2436.2(3) pm, Z = 4. The three Re atoms are located at the corners of a triangle. They are connected by two asymmetric nitrido bridges and two asymmetric chloro bridges. The weakly bent nitrido bridges (Re–N–Re = 152° and 157°) are characterized by Re–N distances of 169 und 207 pm as well as 171 and 207 pm. Re1, in addition, binds a terminal nitrido ligand with Re1–N1 = 166 pm.