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ABSTRACT: The complexes [MCl4(NNR2)] (M = Mo,W; R2 = MePh, Ph2), [MoCl(NNR2)2(PPh3)2]+, [ReCl(NNAr)2(PPh3)2] (Ar = 4-substituted phenyl), [ReCl3(NNR2)2py] (R2 = Ph2, PhMe) and [ReNCl2(PMe2Ph)3] form efficient catalysts for metathesis and ring-opening metathesis polymn. on activation with alkylating agents such as EtAlCl2. These show activities comparable with other reported systems and stereochem. selectivity for the ROMP reaction of norbornene. Possible reaction mechanisms are discussed. [on SciFinder(R)]
Journal of Molecular Catalysis A Chemical 01/1997; 115(1):73-77. · 2.95 Impact Factor
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ABSTRACT: Reaction of the ReIII bis-diazenido starting materials [ReCl(NNC6H4X-4)2(PPh3)2] (X = Cl 1 or Me 2) with excess dppe (Ph2PCH2CH2PPh2) in MeOH-toluene under reflux gave the novel orange-brown, formally 20-electron ReIII bis-diazenido cations [Re(NNC6H4X-4)2(dppe)2]+ (X = Cl or Me) in good yield by addn. of a suitable anion to the cooled reaction mixt. Reaction of 1 and 2 with the more reducing dmpe (Me2PCH2CH2PMe2) ligand gave the formally 20-electron bis-diazenido cation [Re(NNC6H4X-4)2(dmpe)2]+ for X = Cl but the 18-electron mono-diazenido cation [ReCl(NNC6H4X-4)(dmpe)2]+ for X = Me. The structures of [Re(NNC6H4Me-4)2(dppe)2][PF6]·2DMF (5), [Re(NNC6H4Cl-4)2(dmpe)2][PF6] (6) and [ReCl(NNC6H4Me-4)(dmpe)2][PF6] (7) were detd.: 5, triclinic, space group P̅1, a 13.046(3), b 13.250(3), c 12.233(4) Å, α 110.74(2), β 95.86(2), γ 115.83(2)°, Z = 1, R = 0.040; 6 monoclinic, space group P21/c, a 8.992(2), b 21.947(2), c 18.982(2) Å, β 91.45(1)°, Z = 4, R = 0.056; 7 orthorhombic, space group Pnma, a 1
Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry. 01/1995;
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ABSTRACT: The bis(diazenido)technetium(III) complex [TcCl(NNR)2(PPh3)2] (R = C6H4Cl-4) reacted with bidentate ligands L with loss of 1 diazenide ligand to give [Tc(NNR)L2(PPh3)] (L = S2CNR2) and [TcCl(NNR)L(PPh3)2] (HL = maltol) in high yield. With dianionic tetradentate ligands L' complexes cis-[Tc(NNR)L'(PPh3)] [L'H2 = N,N'-bis(salicylidene)ethane-1,2-diamine (salen), HS(CH2)2NMe(CH2)2NMe(CH2)2SH or HO2S(CH2)2NMe(CH2)2NMe(CH2)2SO2H] were obtained. The crystal structure of the complex with L' = salen was detd. It shows pseudo-octahedral coordination about the Tc with the NNR and PPh3 ligands cis. Direct reaction of [TcO4]- with arylhydrazine hydrochlorides generated a diazenide species in situ which reacts with S2CNR2 to give [TcCl(NNR)2(S2CNR2)2] and 2,2'-bipyridine (bipy) to give [TcCl(NNR)(bipy)2]+ isolated as a BPh4- salt. [on SciFinder(R)]
Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry (1972-1999). 01/1994;
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ABSTRACT: The Schiff bases 2-[Ph2P(CH2)nN:CH]C6H4OH (n = 3, (HL1) or 2 (HL2)), 2-(RCH:N)C6H3(OH)X-4 (R = 2-Ph2PC6H4, X = H (HL3); R = 2-C6H4N, X = H (HL4); R = 2-C5H4N, X = Cl (HL5)) were synthesized from the appropriate amine and aldehyde. On deprotonation these all functioned as tridentate monoanionic ligands to give [FeL2]+ and [CoL2]+ with FeIII and CoIII and neutral complexes NiL2 with NiII. The Fe complexes were examd. by Moessbauer spectroscopy which indicated the presence of two Fe sites in [FeL12]+ with a spin-state equil. dependent on both temp. and the counterion. [FeL32]+ showed a single Fe site, again with a spin state dependent on counterion and temp. The crystal structures of HL3 and [CoL32]+ were detd. The distortions in free HL3 predispose it for coordination in a fac geometry to the Co with cis-PPh2 groups, and the changes occurring on coordination are discussed. Reaction of RCHO (R = 2-Ph2PC6H4 or 2-C6H4N) with 2-aminobenzenethiol gave stable thiazoles RCHNHC6H4S-2 which did not ring ope
Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry. 01/1994;
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ABSTRACT: Reaction of [NBu4][TcOCl4] with RNHNH2 (R = aryl) in MeOH leads to red solns. of Tc diazenido species. These species may be derivatized with PPh3 to give the khaki to orange [TcCl(NNR)2(PPh3)2] (1-3; R = Ph, C6H4Cl-4, PhMe-4, resp.) and lime-green [TcCl2(NNC6H4NO2-4)(PPh3)2] (4). These PPh3 derivs. are also easily prepd. directly from [NH4][TcO4]. An x-ray crystal structure of 2 shows the Tc to be trigonal bipyramidal with axial PPh3 ligands. Derivatization of the red Tc diazenido contg. solns. with bidentate DPPE gives orange [TcCl(NNR)(DPPE)2]+ (5-7; R = Ph, C6H4Cl-4, C6H4NO2-4, resp.) isolated as PF6- or BPh4- salts in good yield. These cationic monodiazenido complexes may also be prepd. by substitution reactions of 1-4 with DPPE, or directly from [NH4][TcO4]. X-ray structure details for 5 as PF6- salt: monoclinic, space group C2/c, a 23.808(5), b 13.830(3), c 17.452(4) Å, β 92.53(2)°, Z = 4, R = 0.0988, R' = 0.104. 5 Has slightly distorted trans octahedral geometry with 2 coordinated dppe
Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry (1972-1999). 01/1993;
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ABSTRACT: The redn. of [TcCl4(PPh3)2] with Zn metal in MeCN in the presence of PPh3 gives the orange cryst. [TcCl3(MeCN)(PPh3)2] (1) in good yield. Suitable crystals of 1 were grown, but the crystal structure could not be detd. satisfactorily due to pseudo-symmetry in the crystal lattice. To overcome this problem the crystal and mol. structure of [TcCl3(MeCN){P(C6H4Me-3)3}2] (1a) was detd. Crystals of 1a are triclinic, space group P̅1, a 10.157(2), b 10.302(2), c 22.073(2) Å, α 87.27(2), β 86.66(1), γ 66.87(1)°, Z = 2, R = 0.039, R' = 0.062. 1A exhibits a distorted pseudo-octahedral geometry with 2 trans P(C6H4Me-3)3 groups, 3 meridionally disposed Cl- groups, and a linear terminally N-bound MeCN ligand. The reaction of 1 with the arom. imines 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), and 2,2':6'2''-terpyridine (terpy) gives the blue-black [Tc(bpy)3]2+, [Tc(phen)3]2+ (3), and [Tc(terpy)2]2+ isolated as their [BPh4]- or [PF6]- salts. The crystal and mol. structure of [Tc(bpy)3][PF6]2 (2a) was
Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry (1972-1999). 01/1993;
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ABSTRACT: Reaction of [ReOCl3(PPh3)2] with MePhNNH2 in boiling MeOH gives orange 5-coordinate [ReCl2(NNMePh)2(PPh3)][BPh4] (1). Attempted recrystn. of 1 as its [PF6]- salt led unexpectedly to brown cryst. [ReOCl(NNMePh)(PPh3)2][PF6]2 (2). The structure of 2 was detd. as 5-coordinate with the oxo and hydrazido moieties in the equatorial plane of a trigonal bipyramid, and with the mutually trans-phosphine ligands occupying the axial sites. 1 Is a versatile starting material and reacts with NaS2CNR2 (R = Me, Et) to give red, cryst. ([Re(NNMePh)2(S2CNR2)2][BPh4] (3; R = Me, Et). The structure of 3 (R = Me) was detd. as pseudooctahedral with linear, mutually cis-NNMePh groups and cis-chelating dithiocarbamato ligands. Reaction of 1 with the sterically hindered thiol 2,6-dichlorobenzenethiol (DCTH) gives orange [Re(NNMePh)2(DCT)2(PPh3)][BPh4]. Reaction of the imido precursor [ReCl3(NPh)(PPh3)2] with excess MePhNNH2 gives yellow [ReCl2(NPh)(NNMePh)(PPh3)][BPh4] (4). 1, 2, And 4 contain the formally isoelectronic
Polyhedron 01/1992; 11(2):147-55. · 2.06 Impact Factor
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ABSTRACT: Reaction of [ReCl3(MeCN)(PPh3)2] with the planar pentadentate diacetylpyridinebis(benzoylhydrazone) ligands DAPBH2 and DAP-Me-BH2 and triethylamine in isopropanol under reflux gave the dark brown seven-coordinate complexes [ReCl(L)PPh3], containing the doubly deprotonated pentadentate ligand [L = DAPB(2−)(1); L = DAP-Me-B(2−) (2)]. Complex 1 has been characterized by crystallography. The central rhenium atom in 1 is seven-coordinate, with pentagonal bipyramidal geometry with the axial positions being occupied by the chloride ion and the triphenylphosphine ligand. The DAPB coordinates in a pentadentate manner in the equatorial plane of the complex and the five donor atoms of the doubly deprotonated DAPB(2−) ligand form an approximately planar pentagon. The rhenium atom is slightly displaced out of the ligand plane towards the phosphorus atom. Reaction of 2 with Ag[BF4] in CH2Cl2 at room temperature gave a black complex of stoichiometry [Re(DAP-Me-B)(PPh3)][BF4] (3). Reaction of [MoCl4(MeCN)2] with DAP-Me-BH2 and Et3N in dry CH2Cl2 under reflux gave deep green [MoCl2(DAP-MeB2)] (4), formulated as a seven-coordinate molybdenum(II) complex containing the doubly deprotonated pentadenate DAP-MeBH2 ligand in the equatorial plane of the complex. The Mössbauer spectra of the complexes [FeCl2(DAPBH2)]·H2O (5) and [FeCl(DAPMe-B)(H2O)] (6) were investigated as a function of temperature. The spectrum of 5 was consistent with high-spin seven-coordinate iron(II) and 6 was shown to contain two distinct iron(III) sites; possible structures are discussed.
Polyhedron.