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2,6-Di-tert-butyl-4-iodophenol (1) does not react to the keto carbene 4 under strongly basic conditions and exclusion of oxygen, in contrast to a report in the literature. In the presence of oxygen, however, oxidation takes place. Reaction times and product pattern strongly depend on the concentration of O2. Besides biphenyl 2, diphenoquinone 3, and quinone 5, a new (oxocyclohexadienylidene)bisphenol 6 was isolated, and its molecular structure was determined by X-ray crystallography. A radical mechanism is suggested for the formation of the above products from 1. The bisphenol 6 was also synthesized by thermolysis of the quinone diazide 11 in the presence of 3.

By the reaction of transition metal ions (Cu2.Ni2′) with 1,2-diselenooxalate the first selenooxalato complexes have been synthesized. The structure of the nickel complex, bis(1,2-diselenooxalato)nickelate(II).(BzlPh8P)2[Ni(dso)2], has been determined by X-ray diffraction. The analogous Cu(II) complex. [Cu(dso)2]2, was identified by its ESR spectrum characterized by the following parameter set: go = 2.042 and the 64Cu and 77Se hypertine coupling constants a o co = 79.1 × 10 4 cm 1 and a a Se = 48.6 × 10 4 cm 1 . respectively.

[NEt4]2[Tc(Cl)3(CO)3] was prepared directly from [NBu4][TcO4]. Dissolution of [NEt4]2[Tc(Cl)3(CO)3] in water yielded the aqua ion [Tc(OH2)3(CO)3]+ which, upon titration with 1 eq. of OH−, gave the tetranuclear complex [{Tc(μ3-OH)(CO)3}4] in quantitative yield and of which the structure could be elucidated. Reaction of [{Tc(μ3−OH)(CO)3}4] with HC5Me5 gave the important starting material [(C5Me5)M(CO)3] (M = Tc, Re). To achieve complexes in higher oxidation states with the C5Me5− ligand, oxidation was performed with [Br2] for the rhenium and the corresponding technetium complex. Oxidation in trifluoroacetic acid yielded cis/trans-[(C5Me5)M(Br)2(CO)2] (M = Tc, Re). Oxidation in dichloromethane gave in both cases the seven co-ordinate, 18e− M(III) complex [(C5Me5)MBr(CO)3]+. The structure of the rhenium complex was elucidated. It was found that oxidation took place at the metal centre and the C5Me5− ring to yield [(CO)3M(μ−Br)3M(CO)3] as the counterion.

Complexes of the general formula |M(CO)3[(Ph2PS)2N](CH3CN)| (M = Tc, Re) have been prepared by the reaction of (Et4N)2[M(CO)3X3] (M = Tc, Re; X = Cl, Br) with sodium bis(diphenylthiophosphoryl)amide, Na[(Ph2PS)2N], in acetonitrile. The metal is six-coordinate with facially arranged carbonyl ligands. Bis(diphenylthiophosphoryl)amide is deprotonated and bonded as S,S′-chelate with TcS distances of 2.526(3) and 2.546(3) A. Acetonitrile occupies the sixth coordination position. The rhenium compound is isomorphous and the bonding situation in |Re(CO)3[Ph2PS)2N](CH3CN)| is similar to that in its technetium analogue. (Et4N)[Re(CO)3Br2(CH3CN)] crystallizes from a hot acetonitrile solution of (Et4N)2[Re(CO)3Br3] despite the fact that in solution only [Re(CO)3(CH3CN)3]+ can be detected spectroscopically. It has a facial arrangement of CO groups in an octahedral co-ordination geometry.

The synthesis and characterization of novel indium(III) complexes with pyridine-thiosemicarbazone ligands are reported as well as ligand exchange reactions on the products. 2,6-Diacetylpyridine-bis(thiosemicarbazone), C5H3N(C3N3SH6)2 (H2DAPTSC), and 2-acetylpyridine-thiosemicarbazone, C5H4N(C3N3SH6) (HAPTSC), were reacted with indium(III) halides and indium(III) nitrate, respectively, to give [InX2(HDAPTSC)], {O[In(HDAPTSC)(OH)]2}, [InX2(APTSC)(MeOH)] and [In(APTSC)2]PF6.

[InCl3(L1)(MeOH)] [L1 = pyridine-2,6-bis(acetyloxine), 2,6-C5H3N(C2H3NOH)2] reacts with bidentate ligands by ligand exchange. A seven-coordinate complex of the composition [In(L1)Cl(ox)(OH2)] is formed with potassium oxalate (K2ox). The oxalato ligand occupies the equatorial plane of a pentagonal bipyramid together with the tridentate amine oxime. With sodium 1,2-dicyanoethene-1,2-dithiolate (Na2mnt) the analogous reaction produces a six-coordinate mixed ligand complex, [In(L1)Cl(mnt)], which has a distorted octahedral coordination sphere. Ligands which form four-membered chelate rings like dialkyldithiocarbamates, R2dtc−, or pyridine-2-thiolate, pythio−, are able to replace all ligands of [InCl3(L1)(MeOH)] to form neutral tris chelates. The structure of [In(pythio)3] has been elucidated showing a strong distortion of the coordination polyhedron from the idealized octahedral geometry.

2,6-Bis(acetyloxime)pyridine, 2,6-C5H3N(C2H3NOH)2 (L1), reacts with indium(III) chloride in methanol to give the seven-coordinate complex [InCl3(L1)(MeOH)]. The structurally similar Schiff base ligand 2,6-bis(1-phenyliminoethyl)pyridine (L2), 2,6-C5H3N(C2H3NC6H5)2, however, forms a six-coordinate indium(III) complex of the composition [InCl3(L2)]. The InN bond distances are longer by 0.03–0.12 A in the seven-coordinate compound compared with those in the Schiff base complex. The MeOH ligand in [InCl3(L1)(MeOH)] can be replaced by Cl− or H2O to give the complex anion [InCl4(L1)]− and [InCl3(L1)(OH2)], respectively. The pentagonal-bipyramidal coordination environment of the metal is preserved during these reactions.

The anionic rhenium(I) complex fac-[Re(CO)3Br3]2− has been reacted with thiourea (tu), N,N-dialkylbenzoylthioureas (HR2btu) and N,N-dialkylthiocarbamoylbenzamidines (HR12tcbR2) to give novel mono- and binuclear rhenium(I) complexes. All new compounds are air-stable and non-sensitive against aqueous media. Fac-[Re(CO)3(tu)3] (NO3) is formed from the bromo complex by precipitation of AgBr after addition of AgNO3 and subsequent reaction with thiourea. The compound co-crystallizes with one molecule of (Et4N) NO3 in the monoclinic space group P2 1 /n,a = 143675(3), b = 13.372(1), c = 28.841 (7) A , s = 102.53(1)°, Z = 8 . The mean ReS bond length is 2.529 A. N,N-Dialkylbenzoylthioureas react with (Et4N)2[Re(CO)3)Br3] to form neutral [Re(CO)3Br(HR2btu)] complexes. With the rhenium(I) centers under study they coordinate bidentately, but without deprotonation, which is unusual for this class of chelate ligands. [Re(CO)3Br(HEt2btu)] crystallizes in the triclinic space group P 1 , a = 8.080(2), b = 9.254(3), c = 13.761(5) A α = 76.60(2), s = 88.66(2), γ = 70.92(3)°, Z = 2. The chelate ring shows significant deviations from planarity which underline the absence of an extended π-system. Complexes of different composition are formed with thiocarbamoylbenzamidines depending on the sterical requirements of the individual ligands. A binuclear compound could be isolated with N,N-diethylthiocarbamoylbenzamidinate (Et2tcbH−). [Re2(CO)6−(Et2tcbH)2] crystallizes in the monoclinic space group P2 1 /c, a = 10.859(4), b = 17.409(2), c = 9.159(5) A , s = 79.15(2)°, Z = 2 . Both rhenium atoms are coordinated by three facially arranged carbonyls and a singly deprotonated Et2tcbH− ligand. The sulfur atoms of these ligands act as bridges between the metal centers forming a four-membered Re2S2 ring. Two slightly different ReS bond lengths are observed in this ring system (2.507(2) and 2.545(2) A). Only a mononuclear, anionic complex is formed with the more bulky benzamidine ligand N(N-morpholinylthiocarbonyl)-N′-phenylbenzamidine (Hmorphtcbph). (Et4N) [Re(CO)3Br(morphtcbph)] crystallizes in the triclinic space group P 1 , a = 10.018(4), b = 10.065(4), c = 16.720(7) A , α = 80.90(3), s = 79.82(3), γ = 70.81(4)°, Z = 2 . The rheniumsulfur distance is 2.476(2) A.

Synthesis of N-[2(1H-pyrolylmethyl)]-N′-(4-pentene-3-one-2)ethane-1, 2-diamine has been effected and the compound characterised by X-ray diffraction. Crystal data for C12H19N3O: space group P21/c: a=10.358(3), b=7.953(1), c=15.640(4) A, β=101.63(1)°, V=1261(2) A3 to give Z=4 for D=1.165 g cm−3. Structure solution and refinement based on 2114 reflections converged at R=0.064, Rw=0.079. Reaction of this molecule with Bu4N[TcO(ethylene glycolate)2] results in the formation of a neutral technetium(V) complex [TcOL]. The X-ray structure of this complex confirms a five-coordinate, square based pyramidal geometry with no crystallographic axes of symmetry. Crystal data: orthorhombic space group P212121; a=11.701(1), b=14.949(2), c=7.516(1) A, V=1314.6 A3 to give Z=4 for D=1.68 g cm−3. Structure resolution and refinement based on 2115 reflections converged at R=0.037, Rw=0.033. Reaction of N-[2(1H-pyrolylmethyl)]-N′-(4-pentene-3-one-2)ethane-1,2-diamine with rhenium(V) oxotrichlorobistriphenylphosphine [ReOCl3(PPh3)2] or a rhenium(V) glycolato precursor yields the [ReOL] complex. The compounds have been studied by NMR, UVVis, IR spectroscopy as well as by mass spectrometry. The obtained results have been discussed in terms of the complex formation and the different transition metals.

Diamagnetic nitridotechnetium(V) complexes with tri- and tetradentate azomethine ligands which possess electron withdrawing groups in their periphery can be prepared starting from TcNCl 2 (Ph 3 P) 2 or (in the case of the tetradentate ligands) TcNX 4 − (X = Cl, Br). The products are air stable compounds which have been characterized by elemental analysis, infrared and UV-Vis spectroscopy, NMR and mass spectrometry. The mixed-ligand complex [ N -(2-Ethoxycarbonyl-3-oxo-but-l-en(1)yl)-2-aminophen- olato](triphenylphosphine)nitridotechnetium(V) (C 31 H 28 N 2 O 4 PTc, M r = 622.5) crystallizes monoclinic in the space group C 2/ c . The coordination geometry is a distorted square pyramid with the nitrido ligand at the apex.

Formation de complexes de l'indium(III) avec des thiocarbamates, des xanthates, des thiophosphates alkyles. Ces complexes ont ete isoles a l'etat cristallin. Donnees spectrometriques et analyse elementaire