A neutral mononuclear rhenium(I) complex with a rare -generated triazolyl ligand for the luminescence "turn-on" detection of histidine.

A rare -generated mononuclear rhenium complex [Re(bpt)(CO)(NH)] (1, bpt = 3,5-bis(2-pyridyl)-1,2,4-triazolate) can be used as a "turn-on" luminescent probe for selectively sensing L-histidine against other amino acids. Compound 1 was prepared by reacting Re(CO), 2-cyanopyridine and hydrazine with an formed bpt ligand through cyclization C-N and N-N couplings with its single-side chelating mode arrayed with respect to the Re center. Compound 1 was highly stable and showed a green light MLCT emission in DMF solution at 507 nm upon excitation at 360 nm.

Ring-Opening Polymerization of ε-Caprolactone and Styrene Oxide-CO Coupling Reactions Catalyzed by Chelated Dehydroacetic Acid-Imine Aluminum Complexes.

A series of chelated dehydroacetic acid-imine-based ligands ~ was synthesized by reacting dehydroacetic acid with 2-t-butylaniline, ()-1-phenyl-ethylamine, 4-methoxylbenzylamine, and 2-(aminoethyl)pyridine, respectively, in moderate yields. Ligands ~ reacted with AlMe in toluene to afford corresponding compounds (), (), (), and (). All the ligands and aluminum compounds were characterized by IR spectra, H and C NMR spectroscopy.

Structural Determination of Ruthenium Complexes Containing Bi-Dentate Pyrrole-Ketone Ligands.

A series of ruthenium compounds containing a pyrrole-ketone bidentate ligand, 2-(2'-methoxybenzoyl)pyrrole (), have been synthesized and characterized. Reacting with [(η⁶-cymene)RuCl₂]₂ and RuHCl(CO)(PPh₃)₃ generated Ru(η⁶-cymene)[C₄H₃N-2-(CO-C₆H₄-2-OMe)]Cl () and {RuCl(CO)(PPh₃)₂[C₄H₃N-2-(COC₆H₄-2-OMe)]} (), respectively, in moderate yields. Successively reacting with sodium cyanate and sodium azide gave {Ru(η⁶-cymene)[C₄H₃N-2-(CO-C₆H₄-2-OMe)]X} (, X=OCN; , X=N₃) with the elimination of sodium chloride.

Catalytic transfer hydrogenation and anticancer activity of arene-ruthenium compounds incorporating bi-dentate precursors.

Ruthenium based organometallic compounds are presently a subject of great attention as anticancer drugs and appear to work reasonably well on tumor cells. We develop a series of mononuclear arene-ruthenium compounds incorporating N,O and N,N bidentate ligands, and their activity as anticancer drugs against human hormone-refractory metastatic prostate cancer (HRMPCs) cell lines are investigated. The ruthenium compounds also act as effective catalysts in the transfer hydrogenation of the -C[double bond, length as m-dash]O- → -CH(OH)- system.

Doubly end-on azido bridged mixed-valence cobalt trinuclear complex: Spectral study, VTM, inhibitory effect and antimycobacterial activity on human carcinoma and tuberculosis cells.

Doubly end-on azido-bridged mixed-valence trinuclear cobalt complex, [Co3(L)2(N3)6(CH3OH)2] (1) is afforded by employing a potential monoanionic tetradentate-N2O2 Schiff base precursor (2-[{[2-(dimethylamino)ethyl]imino}methyl]-6-methoxyphenol; HL). Single crystal X-ray structure reveals that in 1, the adjacent Co(II) and Co(III) ions are linked by double end-on azido bridges and thus the full molecule is generated by the site symmetry of a crystallographic twofold rotation axis. Complex 1 is subjected on different spectral analysis such as IR, UV-vis, emission and EPR spectroscopy.

A mixed valent heterometallic Cu(II)/Na(I) coordination polymer with sodium-phenyl bonds.

A mixed valent heterometallic Cu(II)/Na(I) coordination polymer (1) is generated by the reaction of a Schiff base ligand, (6,6'-(1E,1'E)-(2-hydroxypropane-1,3-diyl)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(2-methoxyphenol)) with copper(II) acetate and sodium perchlorate. In addition to the presence of alcohol oxygen-sodium coordination bonds, the single crystal X-ray structure reveals that the 1D coordination polymer is stabilised by the formation of phenyl-sodium η2-bonds, face-to-face π-π contacts and Cu-π interactions.

(Azido-κN){(E)-2-[1-(pyridin-2-yl)ethyl-idene-amino]-phenolato-κ(3) N,N',O}copper(II).

In the title complex, [Cu(C13H11N2O)(N3)], the Cu(II) cation is four-coordinated by an N2O donor set of the tridentate Schiff base ligand and by the terminal N atom of the azide anion, forming a slightly distorted square-planar configuration.

{5,5'-Dihydroxy-2,2'-[(2-hydroxypropane-1,3-diyl)bis(nitrilomethanylyli-dene)]diphenolato}nickel(II) dihydrate.

In the title complex, [Ni(C17H16N2O5)]·2H2O, the Ni(II) ion is four-coordinated by two azomethine N and two phenolato O atoms of the tetradentate Schiff base ligand in a slightly distorted square-planar geometry. In the six-membered ring containing the metal, the azomethine N atoms and the three C atoms of the connecting 1,3-di-amino-propane-2-ol, all atoms except the metal are disordered over two sets of sites with an occupacy ratio of 0.566 (3):0.

Di-aqua-{2,2'-dimeth-oxy-6,6'-[(1E,1'E)-propane-1,3-diylbis(aza-nylyl-idene)bis-(methanylyl-idene)]diphenolato}nickel(II).

In the mol-ecule of the title compound, [Ni(C19H20N2O4)(H2O)2], the central Ni(II) ion lies on a mirror plane and is surrounded by an N2O4 coordination set in the form of a distorted octa-hedron defined by the O atoms of two water mol-ecules and by two phenolic O and two imine N atoms of the tetra-dentate Schiff base ligand. In the crystal, O-H⋯O hydrogen bonds between the water mol-ecules and the phenolic and meth-oxy O atoms of neighbouring mol-ecules lead to the formation of rods propagating parallel to [100].

Aluminum complexes incorporating symmetrical and asymmetrical tridentate pincer type pyrrolyl ligands: synthesis, characterization and reactivity study.

A series of aluminum complexes incorporating substituted symmetrical and asymmetrical tridentate pyrrolyl ligands are synthesized conveniently and the treatment of the derivatives with small organic molecules are analyzed. The reaction of lithiated [C4H2NH(2-CH2NH(t)Bu)(5-CH2NR1R2)], where for 1, R1 = R2 = Me; 2, R1 = H, R2 = (t)Bu, with AlCl3 in diethyl ether affords Al[C4H2N(2-CH2NH(t)Bu)(5-CH2NMe2)]Cl2 (3) and Al[C4H2N(2,5-CH2NH(t)Bu)2]Cl2 (4), respectively, in high yields. Furthermore, subjecting 3 and 4 to reaction with one equiv.

Zirconium complexes incorporated with asymmetrical tridentate pincer type mono- and di-anionic pyrrolyl ligands: mechanism and reactivity as catalytic precursors.

The reactions of Zr(NR(2))(4) (1, R = Me; 2, R = Et) with an asymmetrical tridentate pincer type pyrrole ligand precursor [C(4)H(2)NH(2-CH(2)NH(t)Bu)(5-CH(2)NMe(2))] and treatment of the derivatives with either PhNCS or PhNCO have been carried out and characterized. Reacting Zr(NR(2))(4) (1, R = Me; 2, R = Et) with [C(4)H(2)NH(2-CH(2)NH(t)Bu)(5-CH(2)NMe(2))] generates Zr[C(4)H(2)N(2-CH(2)N(t)Bu)(5-CH(2)NMe(2))](NR(2))(2) (3, R = Me; 4, R = Et) in high yield along with the elimination of 2 equiv of dimethylamine or diethylamine, respectively. Interestingly, while changing the solvent from Et(2)O to CH(2)Cl(2), the complex Zr[C(4)H(2)N(2-CH(2)N(t)Bu)(5-CH(2)NMe(2))][C(4)H(2)N(2-CH(2)NH(t)Bu)(5-CH(2)NMe(2))]Cl (5) is produced by undergoing C-Cl bond cleavage.

End-to-End Thiocyanato-Bridged Helical Chain Polymer and Dichlorido-Bridged Copper(II) Complexes with a Hydrazone Ligand: Synthesis, Characterisation by Electron Paramagnetic Resonance and Variable-Temperature Magnetic Studies, and Inhibitory Effects on Human Colorectal Carcinoma Cells.

The reactions of the tridentate hydrazone ligand, N'-[1-(pyridin-2-yl)ethylidene]acetohydrazide (HL), obtained by condensation of 2-acetylpyridine with acetic hyadrazide, with copper nitrate trihydrate in the presence of thiocyanate, or with CuCl2 produce two distinct coordination compounds, namely a one-dimensional helical coordination chain of [CuL(NCS)] n (1) units, and a doubly chlorido-bridged dinuclear complex [Cu2L2Cl2] (2) (where L=CH3C(O)=N-N=CCH3C5H4N). Single-crystal X-ray structural determination studies reveal that in complex 1, a deprotonated hydrazone ligand L(-) coordinates a copper(II) ion that is bridged to two neighbouring metal centres by SCN(-) anions, generating a one-dimensional helical coordination chain. In complex 2, two symmetry-related, adjacent copper(II) coordination entities are doubly chlorido-bridged, producing a dicopper entity with a Cu⋅⋅⋅Cu distance of 3.

Dichlorido{N'-[(pyridin-2-yl)methyl-idene-κN]acetohydrazide-κN',O}copper(II).

In the title compound, [CuCl(2)(C(8)H(9)N(3)O)], the Cu(II) atom has a distorted square-pyramidal CuCl(2)N(2)O coordination geometry. The tridentate acetohydrazide ligand occupies three basal positions, the fourth basal position being defined by a chloride anion at a distance of 2.2116 (6) Å.

{N'-[1-(2-Pyrid-yl)ethyl-idene-κN]benzo-hydrazidato-κN',O}{N'-[1-(2-pyrid-yl)ethyl-idene-κN]benzohydrazide-κN',O}copper(II) trichloro-acetate.

In the title complex, [Cu(C(14)H(13)N(3)O)(C(14)H(12)N(3)O)](CCl(3)COO), the central Cu(II) ion exhibits a distorted octa-hedral geometry with the two ligands coordinating in an meridional format. The N(4)O(2) ligand environment is defined by two benzoyl O atoms, two pyridyl N atoms and imino N atoms. As evidenced by the bond lengths, the two benzohydrazone ligands exist in distinctively different forms, one of them as a regular neutral ligand and the other as an anionic enolate arising from deprotonation.

Aluminium complexes containing bidentate and symmetrical tridentate pincer type pyrrolyl ligands: synthesis, reactions and ring opening polymerization.

A series of aluminium derivatives containing substituted bidentate and symmetrical tridentate pyrrolyl ligands, [C(4)H(3)NH(2-CH(2)NH(t)Bu)] and [C(4)H(2)NH(2,5-CH(2)NH(t)Bu)(2)], in toluene or diethyl ether were synthesized. Their reactivity and application for the ring opening polymerization of ε-caprolactone have been investigated. The reaction of AlMe(3) with one equiv.

Synthesis and structural studies of lithium and sodium complexes with OOO-tridentate bis(phenolate) ligands: effective catalysts for the ring-opening polymerization of L-lactide.

A series of lithium and sodium complexes with OOO-tridentate bis(phenolate) ligands have been synthesized and fully characterized. The reaction of 2,2'-dihydroxy-3,3',5,5'-tetrakis[(1-methyl-1-phenyl)ethyl]dibenzyl ether (L(1)-H(2)) with different ratios of (n)BuLi in toluene or tetrahydrofuran (THF) gave [Li(2)(L(1)-H)(2)] (1), [Li(4)L(1)(2)] (2), and [Li(2)L(1)(THF)(3)] (3), respectively. Similarly, [Na(L(1)-H)(THF)] (4), [Na(2)(L(1)-H)](2) (5), and [Na(4)L(1)(2)] (6) were prepared by the reaction of L(1)-H(2) and NaN[Si(CH(3))(3)](2) or sodium metal.

Di-μ-azido-bis-({N'-[1-(2-pyrid-yl-κN)ethyl-idene]acetohydrazidato-κN',O}dicopper(II)).

The dimeric title compound, [Cu(2)(C(9)H(10)N(3)O)(2)(N(3))(2)], is located on a crystallographic inversion center. The Cu atom is coordinated by a tridentate anionic hydrazone ligand and two bridging azide ligands in a distorted square-pyramidal coordination geometry. The non-bonding Cu⋯Cu distance is 3.

Bis{N'-[1-(2-pyrid-yl)ethyl-idene-κN]benzohydrazidato-κN',O}nickel(II).

In the title complex, [Ni(C(14)H(12)N(3)O)(2)], the Ni(II) atom lies at the centre of a distorted octahedron formed by two tridentate hydrazone ligands. Inter-molecular hydrogen bonds of the type C-H⋯X (X = N, O) link the complexes into a two-dimensional network.

Azido-(benzoyl-acetonato-κO,O')[1-phenyl-3-(2-pyridylmethyl-imino)but-1-en-1-olato-κN,N',O]cobalt(III).

In the title complex, [Co(C(16)H(15)N(2)O)(C(10)H(9)O(2))(N(3))], the Co(II) atom adopts an octa-hedral coordination geometry by a tridentate Schiff base, a bidentate benzoyl-acetonate and an azide ligand. The imine N atom of the tridentate ligand is trans to the benzoyl O atom of the bidentate ligand and the azide ligand is trans to the acetyl O atom of the bidentate ligand. Non-classical intra-molecular C(ar-yl)-H⋯O hydrogen bonds are present in the structure.

Dichlorido{N'-[1-(2-pyridin-2-yl)ethyl-idene]acetohydrazide-κN',O}copper(II).

In the title compound, [CuCl(2)(C(9)H(11)N(3)O)], the Cu(II) atom is in a distorted square-pyramidal CuCl(2)N(2)O coordination geometry. The tridentate acetohydrazide ligand chelates in a meridional fashion. The chloride ligand in the axial position forms a long Cu-Cl distance of 2.

A new type of asymmetric tridentate pyrrolyl-linked pincer ligand and its aluminum dihydride complexes.

The new pyrrolyl-linked pincer-type ligand, [C(4)H(2)NH(2-CH(2)NH(t)Bu)(5-CH(2)NMe(2))] (1), that has been employed conveniently in high yield by treatment of (2-t-butylaminomethyl)pyrrole with 1 equiv of formaldehyde and dimethylamine hydrochloride each in diethylether and its corresponding aluminum derivative, [C(4)H(2)N(2-CH(2)NH(t)Bu)(5-CH(2)NMe(2))]AlH(2) (2), that has been generated from Me(3)N.AlH(3) using diethylether as a solvent are described. Furthermore, reactions of 2 with 2 equiv of either 1,3-diphenylpropane-1,3-dione in diethylether or phenyl thioisocyanate in dichloromethane interestingly formed [C(4)H(2)N(2-CH(2)NH(t)Bu)(5-CH(2)NMe(2))]Al(PhCOCHCOPh)(2) (3) and [C(4)H(2)N(2-CH(2)NH(t)Bu)(5-CH(2)NMe(2))]Al(SCHNPh)(2) (4), respectively, following deprotonation or hydroalumination reaction kinetics under a dry nitrogen environment.

Deprotonation and reductive addition reactions of hypervalent aluminium dihydride compounds containing substituted pyrrolyl ligands with phenols, ketones, and aldehydes.

The reactivities of [C4H2N(CH2NMe2)2]AlH2 (1) with primary and secondary amines, phenols, ketones, and phenyl isothiocyanate were examined. Reactions of 1 with one or two equivalents of 2,6-dichloroaniline in methylene chloride generated [C4H2N(CH2NMe2)2]AlH(NHC6H3-2,6-Cl2) (2) and [C4H2N(CH2NMe2)2]Al(NHC6H3-2,6-Cl2)2 (3), respectively, following hydrogen elimination. Similarly, the reactions of 1 with one or two equivalents of carbazole afforded [C4H2N(CH2NMe2)2]AlH(NC12H8) (4) or [C4H2N(CH2NMe2)2]Al(NC12H8)2 (5) by deprotonating the acidic N-H of carbazole.

Monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl and ketiminate ligands: synthesis and structural characterization.

A series of monomeric, dimeric, and trimeric calcium compounds containing substituted pyrrolyl or ketiminate ligands were synthesized, and characterized by NMR spectroscopy and single crystal X-ray diffractometry. The reaction of Ca[N(SiMe(3))(2)](2)(THF)(2) with 1 equiv of [C(4)H(3)NH(2-CH(2)NEt(2))] in toluene generates the dimeric complex, [Ca{N(SiMe(3))}[mu-eta(1):eta(5)-{C(4)H(3)N(2-CH(2)NEt(2))}]](2) (1) in which two substituted pyrrolyl ligands bind two Ca centers in a eta(1) and eta(5) fashion. The reaction between Ca[N(SiMe(3))(2)](2)(THF)(2) and 2 equiv of [C(4)H(3)NH(2-CH(2)NEt(2))] in THF yields a monomeric calcium compound Ca[C(4)H(3)N(2-CH(2)NEt(2))](2)(THF)(2) (2) that exhibits a facial octahedral geometry on the central Ca atom.

Bis[N'-(2-pyridylmethyl-ene-κN)benzo-hydrazide-κN']bis-(thio-cyanato-κN)cobalt(II).

In the title complex, [Co(NCS)(2)(C(13)H(11)N(3)O)(2)], the Co(II) centre adopts a distorted octa-hedral coordination geometry with two cis-bidentate Schiff base ligands and two cis thio-cyanate ligands. The Schiff base ligand coordinates via the imine N and pyridine N atoms. The Co(II) atom lies on a crystallographic twofold rotational axis.

Dichlorido{2-[2-(dimethyl-ammonio)ethyl-imino-meth-yl]-6-methoxy-phenolato}zinc(II).

The structure of the title complex, [ZnCl(2)(C(12)H(18)N(2)O(2))], contains a zwitterionic Schiff base ligand. The complex adopts a distorted tetra-hedral coordination geometry around the metal centre with the Schiff base ligand coordinated in a bidentate fashion via the imine N and phenolate O atoms. In the crystal, inter-molecular N-H⋯O and C-H⋯Cl hydrogen bonds link the mol-ecules into chains parallel to the c-glide planes.