Anionic Amido Research Articles

Anionic Amido N‐Heterocyclic Carbenes: Synthesis of Covalently Tethered Lanthanide–Carbene Complexes

Anionic Amido N‐Heterocyclic Carbenes: Synthesis of Covalently Tethered Lanthanide–Carbene Complexes

Anionic amido N-heterocyclic carbenes: synthesis of covalently tethered lanthanide-carbene complexes.

Organolanthanides with amido-tethered N-heterocyclic carbenes: a new bidentate ligand that tethers an N-heterocyclic carbene group to a trivalent lanthanide complex (samarium, depicted, N′′=N(SiMe3)2; or yttrium) affords the first organolanthanide amido–carbene complexes and an opportunity to explore the strength and reactivity of the early metal–N-heterocyclic carbene fragment.

Supramolecular assembly of linear trinickel complexes incorporating metalloporphyrins: a novel one-dimensional polymer and oligomer

One-dimensional polymeric or oligomeric chains, in which various linear trinickel complexes linked to the axial sites of metalloporphyrins by the combination of self-assembly and coordination chemistry, have been constructed. A carboxylate group of carboxylpyridine was attached to the end of linear trinickel complexes to produce the linear building blocks, Ni3(dpa)4X2 [X = 4-PyCOO− (1) or 3-PyCOO− (2)], which was then reacted with metalloporphyrins to form stable polymers or oligomers. The new self-assembled oligomeric chain, [Ni3(dpa)4(4-PyCOO)2][ZnTPP]2 (3), and two novel self-assembled one-dimensional polymeric chains, {[Ni3(dpa)4(4-PyCOO)2][MnTPP]}n(ClO4)n (4), and {[Ni3(dpa)4(3-PyCOO)2][MnTPP]}n(ClO4)n (5), [dpa− = di(α-pyridyl)amido anion; TPP = meso-tetraphenylporphyrinato dianion], have been synthesized and their structures were determined by X-ray diffraction. The UV/vis spectra indicate the absence of any noticeable interactions between the linear trinickel units and metalloporphyrins in these chains. The magnetic susceptibility measurements in the solid state show that both polymers 4 and 5 have a very weak ferromagnetic interaction.

Solid state structures of homo- and hetero-bimetallic alkali metal complexes containing the dianion of (S)-N-(α-methylbenzyl)allylamine

Dilithiation of the chiral amine (S)-N-(α-methylbenzyl)allylamine in the absence of a coordinating Lewis donor results in formation of crystals of a cyclic hexamer, {[(S)-α-(PhC(H)Me)(CH2CHCHLi)N]Li}6, 1, (rhombohedral, R3) while the addition of tmeda (N,N,N′,N′-tetramethylethylenediamine) leads to deaggregation and formation of the dimer, {[(S)-α-(PhC(H)Me)(CH2CHCHLi)N]Li·(tmeda)2}2, 2 (monoclinic, P21). Reaction with nBuLi followed by nBuNa leads to crystals of a cyclic mixed metal tetramer coordinated with thf, {[(S)-α-(PhC(H)Me)(CH2CHCHNa)N]Li·(thf)}4, 3 (orthorhombic, P212121). The three bimetallic complexes have been characterised by single crystal X-ray diffraction, NMR and elemental analysis. The allyl moieties in all three complexes retain the bonding pattern expected in an N-allylamine (–N(M)—CH2–C(H)C(H)M′, M = Li, M′ = Li or Na) rather than forming a delocalised dianion or an enamide. The anionic amido N and the terminal vinylic C centres form multiple short bonds to all metal centres which in turn form short interactions with all atoms in the allyl groups, and in 1 with the closest Ph carbons.

Two Polymeric Linear Tri‐nickel(II) Complexes: [Ni3(μ3‐dpa)4(C4O4Me)]n(BF4)n and [Ni3(μ3‐dpa)4(N3)]n(PF6)n Synthesis, Structural Characterization and Magnetic Properties

AbstractTwo new linear tri‐nickel(II) complexes with an infinite polymeric chain, [Ni3(μ3‐dpa)4(C4O4Me)](BF4) 1 and [Ni3(μ3‐dpa)4(N3)](PF6) 2, [dpa− = di(α‐pyridyl)amido anion], have been synthesized and their structures were determined by X‐ray diffraction. Compound 1 crystallizes in the monoclinic system, space group C 2/c, with a = 19.9078(3), b = 13.2986(2), c = 37.6622(5) Å, β = 94.091(1)°, Z = 8. Compound 2 crystallizes in the monoclinic system, space group P 21/n, with a = 13.323(4), b = 23.217(3), c = 17.528(5) Å, β = 94.42(3)°, Z = 4. The two complexes are described as one‐dimensional systems with the (C4O4Me)−, 1, or N3−, 2, serving as a μ‐(1,3) bridged ligand at the two axial sites of each [Ni3(μ3‐dpa)4]2+ fragment. The Ni‐Ni distances of 2.400(1) and 2.402(1) in 1 and 2.389(2), 2.385(2) in 2 are obviously shorter than those of 2.4325(7), 2.4356(7) in the monomeric complex [Ni3(μ3‐dpa)4(N3)2] 3. The magnetic properties of complexes 2 and 3 were studied by susceptibility measurements vs temperature. The χM vs T plots of both complexes show a strong antiferromagnetic behavior. The simulated J13 values are −95 cm−1 and −97 cm−1 for 2 and 3, respectively.

Further Study of the Linear Trinickel(II) Complex of Dipyridylamide

The title compound, Ni3(dpa)4Cl2 (dpa = di(2-pyridyl)amido anion), first reported 30 years ago, structurally characterized in 1991, has been obtained in two new crystal forms, Ni3(dpa)4Cl2·2CH2Cl2 (tetragonal, space group I4, with a = 27.3046(7) A, c = 12.2452(2) A, Z = 8) and Ni3(dpa)4Cl2·THF (orthorhombic, space group Pccn, with a = 12.673(1) A, b = 14.138(3) A, c = 23.890(2) A, Z = 4). They have been examined structurally, and the magnetic properties of one of them determined from 2 to 300 K. Also the proton NMR spectrum has been recorded. These data allow the following conclusions to be drawn: (1) the molecular structure is invariant in the three crystalline forms and has a symmetrical chain of nickel atoms, (2) the terminal metal atoms each have two unpaired electrons, while the central one is typical of diamagnetic square-planar NiII complexes, (3) the magnetic moments of the two terminal nickel(II) ions display antiferromagnetic coupling, with 2J = −108 cm-1, and (4) the Ni3 chain remains symmetr...

Tetrahydroquinolinyl Amido and Indolinyl Amido Complexes of Tantalum as Models for Substrate−Catalyst Adducts in Hydrodenitrogenation Catalysis

The reactions of TaCl5 with Me3SiNC9H10 or LiNC9H10, where [NC9H10]- = tetrahydroquinolinyl (the amido anion of tetrahydroquinoline), afford selective preparative routes to the complete series of amido halide complexes of tantalum(V) Ta(NC9H10)nCl5-n for n = 1−5 (compounds 1−5, respectively). The monokis(tetrahydroquinolinyl) complex is isolated as an ether adduct Ta(NC9H10)Cl4(OEt2) while the complexes Ta(NC9H10)nCl5-n (n = 2−5) are found to be base-free, monomeric species. The related complexes of indolinyl [NC8H8]- (the amido anion of indoline), Ta(NC8H8)nCl5-n(THF) for n = 1 (6) or 2 (7), have been prepared from TaCl5, Me3SiNC8H8, and THF. An X-ray structural determination of Ta(NC9H10)2Cl3 (2) reveals that it adopts a trigonal bipyramidal geometry with equatorial amido ligands that are closer to lying parallel (within) than perpendicular to the TBP equatorial plane. Routes to mixed-ligand aryloxide−amide complexes have been developed from either aryloxide or amido precursors but not from both. Thus, ...

Synthesis of Group 6 metalla-(aza)-crown ether tetracarbonyl complexes with potentially anionic amido groups. The influence of Li+, Mg2+, and Al3+ cations on the susceptibility of the carbonyl ligand to nucleophilic addition of alkyl/aryl carbanions and hydride

Synthesis of Group 6 metalla-(aza)-crown ether tetracarbonyl complexes with potentially anionic amido groups. The influence of Li+, Mg2+, and Al3+ cations on the susceptibility of the carbonyl ligand to nucleophilic addition of alkyl/aryl carbanions and hydride

ChemInform Abstract: Formation in Solution, Synthesis and Crystal Structure of μ‐Oxalatobis(bis(2‐pyridylcarbonyl)amido)dicopper(II).

AbstractCu(II) promotes the hydrolysis of the triazine (I) yielding bis(pyridylcarbonyl)amido‐copper(II) complexes.

ChemInform Abstract: Preparation and Characterization of New Terdentate Aminodiphosphines and Corresponding Vanadium(III) Dialkylamides.

AbstractThe new terdentate aminodiphosphines (IV) are prepared and transformed into their Li amides (VI) according to the scheme.

Formation in solution, synthesis and crystal structure of μ-oxalatobis[bis(2-pyridylcarbonyl)amido] dicopper(II)

The compound μ-oxalatobis[bis(2-pyridylcarbonyl)amido] dicopper(II), [Cu 2{(NCsH 5CO) 2N} 2- (C 2O 4)] was synthesized and characterized by spectroscopy, EPR and diffraction methods. It crystallizes in the triclinic space group P 1 with cell constants: a=7.6793(6), b=9.238(2), c=10.007(2) Å, α=83.80(1), β=68.37(1) and γ=69.44(1)°; V=617.7(3) Å 3, D (calc., Z=2)=1.80 g cm −3, M r=667.6, F(000)=336, λ, (Mo Kα)=0.71069 Å, μ (Mo Kα)=17.895 cm −1 and T=295 K. A total of 3587 data were collected over the range of 1 ⩽ θ ⩽ 30°; of these, 2391 (independent and with I⩾2σ( I)) were used in the structural analysis. The final R and R w residuals were 0.049 and 0.053, respectively. The structure consists of neutral centrosymmetrical binuclear entities in which C 2O 4 2− acts in an asymmetrically bis-bidentate fashion. Each copper atom is in a square-pyramidal environment with the three nitrogen atoms of bis(2-pyridylcarbonyl)- amido anion and an oxygen atom of oxalate in the basal plane and another oxygen atom of oxalate occupying the apical position. The stability constants of the oxalato complexes of bis(2-pyridylcarbonyl)amidocopper( II) have been determined in dimethyl sulphoxide solution: log β 111=12.22 ± 0.05, log β 110=7.0 ± 0.1 and logβ 210=10.25 ± 0.1 at 25 °C and 0.1 mol dm −3 tetra-n-butylammonium perchlorate. Coordination modes of oxalate for this system are compared in DMSO and water in the light of thermodynamic and structural parameters

Preparation and characterization of new terdentate aminodiphosphines and corresponding vanadium(III) dialkylamides

The new amines, HN(CH 2CH 2PR 2) 2 (R = Me, Et), have been prepared by the nucleophilic substitution of halide in HN(CH 2CH 2Cl) 2·HCl or the free amine by the corresponding dialkylphosphido anions. The new amines are readily deprotonated by the action of alkyl lithium reagents. Action of the amido anion, −N(CH 2CH 2PMe 2) 2, on VCl 3·3THF leads to the new ternary amide Cl 2VN(CH 2CH 2PMe 2) 2, from which a new class of organovanadium amido complexes can be obtained by reaction with alkyl or aryl lithium reagents.

ChemInform Abstract: Copper(II)‐Assisted Hydrolysis of 2,4,6‐Tris(2‐pyridyl)‐1,3,5‐triazine. Part 1. Crystal Structures of (Bis(2‐pyridylcarbonyl)amido)(2‐pyridylformamide)copper(II) Perchlorate Monohydrate and (Bis(2‐pyridylcarbonyl)amido)copper(II) Perchlorate

2,4,6-Tris(2-pyridyl)-1,3,5-triazine (tptz) undergoes hydrolysis in the presence of copper(II) nitrate yielding mainly [bis(2-pyridylcarbonyl)amido]copper(II) and free 2-picolinamide (2-pyridylformamide, NC5H4CONH2). Two new compounds of formulae [Cu{(NC5H4CO)2N}(NC5H4CONH2)]ClO4·H2O (1) and [Cu{(NC5H4CO)2}]ClO4(2), where (NC5H4CO)2N– is the bis(2-pyridylcarbonyl)amido anion, have been obtained from aqueous solutions of tptz and copper(II) perchlorate. Crystals of (1) are monoclinic with a= 8.443(4), b= 27.145(12), c= 9.781 (5)A, β= 100.40(6)°, space group P21/n, and Z= 4. Crystals of (2) are tetragonal with a=b= 8.071 (5), c= 21.291 (8)A, space group P41, and Z= 4. The structure of (1) is made up of [Cu{(NC5H4CO)2N}(NC5H4CONH2)]+ mononuclear cations plus semi-co-ordinated perchlorate anions and water of crystallization. The copper(II) ion is in a distorted octahedral environment: the three nitrogen atoms of the (NC5H4CO)2N– ligand and the pyridinic one of the 2-picolinamide form a distorted square plane around the copper while the axial positions are occupied by the oxygen atom of the picolinamide and by an oxygen atom of the perchlorate anion. The structure of (2) consists of bis(2-pyridylcarbonyl)amido-bridged copper(II) one-dimensional chains and non-co-ordinated perchlorate anions. The copper(II) ion has a co-ordination geometry which approximates to trigonal bipyramidal: the apices and one of the equatorial positions of the bipyramid are occupied by the two nitrogen atoms of the pyridine rings and the imine-nitrogen atom respectively, whereas the two other equatorial positions are filled by the two carbonyl-oxygen atoms of another bis(2-pyridylcarbonyl)amido ligand. The structure of (1) allows the nature of the two main products of the copper(II)-assisted hydrolysis of tptz to be established and the structure of (2) shows the ability of the bis(2-pyridylcarbonyl)amido anion to act as a bridging ligand with transition metal ions.

Copper(II)-assisted hydrolysis of 2,4,6-tris(2-pyridyl)-1,3,5-triazine. Part 1. Crystal structures of [bis(2-pyridylcarbonyl)amido](2-pyridylformamide)-copper(II) perchlorate monohydrate and [bis(2-pyridylcarbonyl)amido]-copper(II) perchlorate

2,4,6-Tris(2-pyridyl)-1,3,5-triazine (tptz) undergoes hydrolysis in the presence of copper(II) nitrate yielding mainly [bis(2-pyridylcarbonyl)amido]copper(II) and free 2-picolinamide (2-pyridylformamide, NC5H4CONH2). Two new compounds of formulae [Cu{(NC5H4CO)2N}(NC5H4CONH2)]ClO4·H2O (1) and [Cu{(NC5H4CO)2}]ClO4(2), where (NC5H4CO)2N– is the bis(2-pyridylcarbonyl)amido anion, have been obtained from aqueous solutions of tptz and copper(II) perchlorate. Crystals of (1) are monoclinic with a= 8.443(4), b= 27.145(12), c= 9.781 (5)A, β= 100.40(6)°, space group P21/n, and Z= 4. Crystals of (2) are tetragonal with a=b= 8.071 (5), c= 21.291 (8)A, space group P41, and Z= 4. The structure of (1) is made up of [Cu{(NC5H4CO)2N}(NC5H4CONH2)]+ mononuclear cations plus semi-co-ordinated perchlorate anions and water of crystallization. The copper(II) ion is in a distorted octahedral environment: the three nitrogen atoms of the (NC5H4CO)2N– ligand and the pyridinic one of the 2-picolinamide form a distorted square plane around the copper while the axial positions are occupied by the oxygen atom of the picolinamide and by an oxygen atom of the perchlorate anion. The structure of (2) consists of bis(2-pyridylcarbonyl)amido-bridged copper(II) one-dimensional chains and non-co-ordinated perchlorate anions. The copper(II) ion has a co-ordination geometry which approximates to trigonal bipyramidal: the apices and one of the equatorial positions of the bipyramid are occupied by the two nitrogen atoms of the pyridine rings and the imine-nitrogen atom respectively, whereas the two other equatorial positions are filled by the two carbonyl-oxygen atoms of another bis(2-pyridylcarbonyl)amido ligand. The structure of (1) allows the nature of the two main products of the copper(II)-assisted hydrolysis of tptz to be established and the structure of (2) shows the ability of the bis(2-pyridylcarbonyl)amido anion to act as a bridging ligand with transition metal ions.

Crystal and molecular structure of a nickel(II) compound derived from 2-methylpropane-1,2-diamine: [Ni(C 18H 21N 4)]ClO 4

Crystal of the title compound are monoclinic, a = 19.25(4), b = 13.91(1), c = 14.66(3) Å, β = 94.56(2)°, space group B2 1/ a. A three dimensional X-ray analysis of the structure was made with counter data (2244 independent reflections). The structure was solved by conventional Patterson and Fourier methods and refined by block-diagonal least-squares to R 0.058. The monocation contains an [NiN 4] four co-planar polyhedron with NiN distances of 1.848(6) Å (anionic amido), 1.875(6) and 1.880(5) Å (azomethine) and 1.928(6) Å (primary amine). The ligand is an unusual Schiff base combination of a dimer of 2-aminobenzaldehyde with a terminal diamine. The 1H n.m.r spectra of the salts of this cation are discussed in the light of this structure, and ‘covalent hydration’ is suggested as an explanation of the observed differences in aqueous solution.