2847-14-5

Upstream product

• 1121-60-4 pyridine-2-carbaldehyde 
• 107-15-3 ethylenediamine 

Downstream Products

• 4608-34-8 N,N'-bis(2-pyridylmethyl)ethylenediamine 
• 1426946-32-8 N¹,N²-bis(4-chlorobenzyl)-N¹,N²-bis(pyridin-2-ylmethyl)ethane-1,2-diamine 
• 140-28-3 N,N'-Dibenzylethylenediamine 
• 884482-55-7 [Cu₂(1,2-bis(2'-pyridylmethyleneamino)ethane)(PPh₃)2I₂] 
• 1363649-73-3 N⁽¹⁾,N⁽²⁾-diphenyl-N⁽¹⁾,N⁽²⁾-di(pyrido[1,2-a]indol-10-yl)ethane-1,2-diamine 
• 882522-33-0 3,3'-(ethane-1,2-diyl)bis(2-(pyridin-2-yl)thiazolidin-4-one) 

Relevant academic research and scientific papers

Copper(II) Schiff base complexes and their mixed thin layers with ZnO nanoparticles

Cu(II) complexes with Schiff bases derived from ethylenediamine (en) and 2-pyridinecarboxaldehyde (pyca), 2,5-dimethoxybenzaldehyde (dmbaH) or 4-imidazolecarboxaldehyde (4Him) were obtained and studied by elemental analysis, UV-VIS and IR spectra. Zinc oxide was synthesized using a simple homogeneous precipitation method with zinc acetate as a starting material. Thin layers of the studied Cu(II) complexes were deposited on Si(111) or ZnO/Si(111) substrates by a spin coating method and characterized with a scanning electron microscopy (SEM/EDS), atomic force microscopy (AFM) and fluorescence spectroscopy. For Cu(II) layers the most intensive fluorescence bands due to intra-ligand transitions were observed between 462 and 503 nm. The fluorescence intensity of thin layers was corelated to the rotation speed. In the case of the [Cu(II)(en(4Him)2)Cl2](2a)/ZnO/Si and [Cu(en(dmbaH)2)Cl2](3a)/ZnO/Si layers the quenching of the emission band from ZnO at 440 nm (λex = 330 nm) associated with various intrinsic or extrinsic lattice defects was noted. [Figure not available: see fulltext.]

Nickel(II) complexes incorporating pyridyl, imine and amino chelate ligands: Synthesis, structure, isomer preference, structural transformation and reactivity towards nickel(III) derivatives

Facile condensation of 2-acetylpyridine with ethylenediamine in a 1:1 or 2:1 molar ratio yielded two neutral ligands with different denticity: 1-amino-4-(2-pyridyl)-3-azapent-3-ene (tridentate, L1) and 2,7-bis(2-pyridyl)-3,6-diazaocta-2,6-diene (tetradentate, L3), respectively. Replacing the ketone with 2-pyridinecarboxaldehyde gave a similar set of condensates (L2 and L4). The tridentate mono-Schiff bases (L1 and L2) react smoothly with Ni(ClO 4)2·6H2O furnishing the brown bis-chelate complexes (1a and 1b) with an NiN6 coordination sphere, while the tetradentate bis-Schiff bases (L3 and L4) form green pseudo-octahedral complexes (2a and 2b) in which NiII is present in an N4O2 coordination environment. The isomer specificity for both types of complexes is conspicuous from the representative X-ray structures of 1a and 2a. cis-trans-cis and cis-cis-trans isomers are found exclusively for 1 and 2, respectively. The crystal structure of 2a reveals O-H...O hydrogen bond interactions assembling alternating cations and anions in an infinite chain-like array. Cyclic voltammetric measurements of 1 and 2 in MeCN solution show a quasi-reversible one-electron oxidation near 0.95 and 0.87 V (vs. SCE), respectively, attributed to a NiIII-Ni II redox couple. Another irreversible NiIV-Ni III redox response was observed at higher potential near 1.70 and 1.80 V (vs. SCE) for 1 and 2, respectively. Complexes 1 and 2 display a weak, broad d-d transition band along with a charge-transfer transition. Magnetic susceptibility measurements (at 298 K) confirmed that the spin states of the NiII centres in 1 and 2 are same, S = 1, in agreement with an octahedral configuration. Complexes 1 form stable reddish-brown NiIII complexes (3) under exhaustive constant-potential electrolysis treatment. The NiIII complexes display axial EPR spectra both at 298 K and 77 K with g⊥ > g∥ indicating the presence of an unpaired electron primarily on the metal centre. Complexes of type 1 and 3 exhibit virtually superimposable cyclic voltammograms in a reverse electrode scan study which confirms no change in the coordination sphere on going from 1 to 3. The effective magnetic moment values (ca. 2.10 μB) of 3 suggest a significant orbital contribution to the paramagnetism, consistent with a tetragonally distorted low spin 3d7 system. A colour change phenomenon has been observed for type 2 complexes. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Synthesis of three new branched octadentate (N8) Schiff Base and competitive Lithium-7 NMR study of the stoichiometry and stability constant of Mn2+, Zn2+ and Cd2+ complexes in acetonitrile – [(BMIM)(PF6)] mixture

Three new branched hexadentate amines, have been synthesized. Condensation with picolinaldehyde in methanol leads to produce three new Schiff base, with two 2-pyridylmethyl pendant arms. 7Li NMR spectroscopy was used to investigation the stability and stoichiometry information of a Li+ complex with three symmetrical branched Schiff base (Sc.B.1), (Sc.B.2) and (Sc.B.3) in 0–100, 25–75, 50-50 and 75–25 w/w% acetonitrile – [(BMIM)(PF6)] ionic liquid mixture solution. A competitive 7Li NMR manner was also used to probe the complexation of Schiff bases with Mn2+, Zn2+ and Cd2+ ions in the same solvent systems. The stability constants of the resulting complexes were estimated from computer fitting of the mole ratio information to an equation that relates the observed chemical shifts to the stable constant. There is a reverse relevance of the complex stability and the amount of ionic liquid in the solvent mixture. In of the all experimented solvent mixture, the stability of the resulted 1:1 complexes were found to change in the order M-Sc.B.1>M-Sc.B.2>M-Sc.B.3 and Cd2+> Mn2+> Zn2+.

Effect of N, N'-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) schiff base on the thermophysical properties of ionic liquids in N, N -dimethylformamide solutions at 298.15 K

Various thermophysical properties, densities, electrical conductances, viscosities, and refractive indices of two ionic liquids, 1-pentyl-3- methylimidazolium bromide ([PnMIm]Br) and 1-propyl-3-methylimidazolium bromide ([PMIm]Br, in the presence of N,N'-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) Schiff base in N,N-dimethylformamide (DMF) solutions have been measured at 298.15 K. These data have been used to calculate the standard partial molar volumes, Vφ0, partial molar volumes of transfer, ΔtrVφ0, ion association constants, Ka, limiting molar conductivities, λ0, viscosity B-coefficients, and molar refractions, RD, for the solutions studied. These parameters decrease with increasing BPIE concentration and increase with increasing alkyl chain length of ionic liquids. The results were interpreted in terms of cosphere overlap model and solute-solvent interactions. In general, it is concluded that there is an enhancement in the nonpolar-nonpolar interactions between the BPIE Schiff base and the ionic liquid.

Synthesis and structures of two cobalt(III) complexes with N4 donor ligands: Isolation of a unique bis-hemiaminal ether ligand as the metal complex

Two cobalt(III) complexes, [CoL1(N3) 2]ClO4·H2O (1) and [CoL 2(N3)2]NO3 (2), where L1 = N,N′-bis-(2-pyridylmethyl)-1,2-ethanediamine, L2 = N,N′-bis-(1-methoxy-1-pyridin-2-yl-methyl)-ethane-1,2-diamine and both ligands are tetradentate N4 donors, have been prepared and characterized by elemental analysis, IR and UV-Vis spectroscopy, cyclic voltammetry and single crystal X-ray diffraction studies. Both compounds assume an asymmetric cis-octahedral (N2/N2) geometry. Complex 1 crystallizes in the orthorhombic space group Pbca with cell dimensions a = 9.7593(2) A?, b = 16.8640(3) A?, c = 25.8206(5) A?, Z = 8, whereas complex 2 crystallizes in the monoclinic space group P21/c with cell dimensions a = 14.437(3) A?, b = 15.596(3) A?, c = 19.187(3) A?, β = 93.642(2), Z = 8. In complex 2, a new bis-hemiaminal ether ligand was found to be "trapped". Hemiaminal ethers are known to be very unstable intermediates and no crystal structure of any bis-hemiaminal ether has been reported to date. Complex 2 represents a uniquely stable system containing the trapped bis-hemiaminal ether L2.

Nitric oxide reactivity of a manganese(II) complex leading to nitrosation of the ligand

Manganese(II) complexes, [Mn(L)(Cl)2], 1 and [Mn(L)(H2O)2](ClO4)2, 2 {L = N1,N2-bis((pyridine-2-yl)methyl)ethane-1,2-diamine} were prepared and characterized. In acetonitrile solution, complex 1 did not react with nitric oxide gas. However, addition of nitric oxide gas to the acetonitrile solution of complex 2 resulted in unstable Mn(II)-nitrosyl intermediate. The formation of nitrosyl intermediate was evidenced by UV-Vis, solution FT-IR, 1H NMR spectral studies. Subsequently, Mn(II) center in the complex 2 was undergone reduction to Mn(I) with a simultaneous N-nitrosation of the ligand. The N-nitrosated ligand was isolated and characterized. It should be noted that the corresponding Cu(II) complex of the same ligand in presence of nitric oxide was not found to yield Cu(II)-nitrosyl.

Peroxide-Templated Assembly of a Trimetal Neodymium Complex Single-Molecule Magnet

In this work, we present a trimetal neodymium complex with two notable qualities. First, the assembly of the complex is templated by peroxide derived from atmospheric oxygen. Second, the bulk material behaves as a superparamagnet, implying that the individual complexes are molecular magnets. Peroxide-templated assembly is possible because of the confluence of the high oxophilicity of neodymium along with the use of an azeotropic distillation synthesis method, which excludes water but admits oxygen. SQUID magnetometry measurements show an extremely high magnetic susceptibility as well as a lack of remanence.

Unexpected diversity and novel features within a family of new azide-bridged MnII complexes of pyridyl/imine ligands

A family of tetradentate ligands, [N,N′-bis(pyridine-2-yl)]ethane-1, 2-diamine (L1), [N,N′-bis(pyridine-2-yl)]propane-1,3-diamine (L2) and [N,N′-bis(pyridine-2-yl)]butane-1,4-diamine (L3) has been prepared. These ligands differ only in the number of CH2 groups separating two pyridyl/imine moieties, however, in reactions with MnII and N-3 salts, they produce structurally very diverse solids; [Mn2(L1) 3(N3)]n(ClO4)3n (1), [Mn2(L2)2(N3)2](PF6) 2 (2) and [Mn2(L3)(N3)2] n(ClO4)2n (3). Complexes 1, 2 and 3 consist of azido-bridged magnetically dilute Mn2 pairs, arranged as 1-D, discrete and 2-D arrays, respectively. In these materials, the connection between Mn centers within the dinuclear entities occurs through mono-1,3-N-3, bis-1,3-N-3 and bis-1,1-N-3 bridges, respectively, for 1, 2 and 3. Bulk magnetic measurements reveal that the coupling within such units is antiferromagnetic (J = -1.8 cm-1, 1; J = -4.8 cm-1, 2) and ferromagnetic (J = +1.45 cm-1, 3), depending on whether the N-3 binding mode is end-to-end (EE) or end-on (EO). The reported values are given according to the convention H = -2JS1S2 for the spin-Hamiltonian. the Royal Society of Chemistry 2006.

Synthesis, characterization and DNA interaction of copper (II) complexes with Schiff base ligands derived from 2-pyridinecarboxaldehyde and polyamines

A series of copper (II) complexes a-d with Schiff bases ligands derived from the condensation reactions between 2-pyridinecarboxaldehyde and different polyamines (ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine) were synthesized and characterized by elemental analysis, FT-IR spectroscopy, HRMS, molar conductance and molecular modeling studies. The interactions of the copper complexes a-d with DNA were investigated by the UV spectra, viscosity measurements and gel electrophoresis under physiological conditions. The experimental results indicated that four complexes could bind to DNA via an intercalative mode and showed a different DNA cleavage activity with the sequence: d > c > a > b.

Conductometric study of ionic liquids in the presence of N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) Schiff base in acetonitrile solutions at 298.15 K

In recent years, Schiff bases and their metal complexes in the presence of ionic liquids (ILs) have been used in synthesis of various chemical compounds. To better understanding of ionic liquid influence on these processes, it is required to obtain information about the ion association behavior of the ionic liquids. Therefore, in this work, the molar conductivities of the ILs [RMIm]X (R= propyl, pentyl, and hexyl; X= Br- and Cl-) in different concentrations of N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) Schiff base + acetonitrile solutions were determined at 298.15 K. The obtained conductivity data were analyzed by low concentration Chemical Model (lcCM) conductivity equation to calculate the limiting molar conductivities (Λ0) and ion association constants (KA). The results show that BPIE, alkyl chain length of cation, and anion type have effect on the ionic association process of the ILs. The Λ0 and KA values decrease as the Schiff base concentration, alkyl chain length of cation, and anion size increase in the solution. The association constants were also used to calculate the standard Gibbs energy (ΔG0A) of ion-pairing association. The resulted ΔG0A values are negative and become more negative as the alkyl chain length of the cation and the size of anion increase. The large negative values of the standard Gibbs energy obtained for [HMIm]Br indicates the more spontaneity and the more feasibility of the association process for this ionic liquid.