Synthesis and Complexation of a Chiral Sexidentate Pendant-Arm Macropolycyclic Polyamino Acid

2002 ◽  
Vol 55 (10) ◽  
pp. 667 ◽  
Author(s):  
G. Wei ◽  
T. W. Hambley ◽  
G. A. Lawrance ◽  
M. Maeder
Keyword(s):  
Carboxylic Acid ◽  
Metal Ions ◽  
Secondary Amines ◽  
Distorted Octahedral Geometry ◽  
Monoclinic Space Group ◽  
Basic Solution ◽  
Polyamino Acid ◽  
Pendant Arm ◽  
Distorted Octahedral ◽  
Acyclic Complex

The reaction of the acyclic complex ion (methyl (SS,SS)-3-[(2�-aminocyclohexyl)amino]-2-[(2�-aminocyclohexyl)-aminomethyl]propionate)copper(II) with formaldehyde and nitroethane in basic solution yields the pendant-arm macrocyclic complex (SS,SS)-(methyl-15-methyl-15-nitro-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane-4-carboxylate)copper(ii) ion. Reduction with zinc in hydrochloric acid yields the hydrochloride salt of the pendant-arm macrocycle (SS,SS)-15-amino-15-methyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane-4-carboxylic acid (1), separated into and isolated as the major trans (1a) and minor cis (1b) isomers. Co-ordination of (1) to several metal ions [CoIII, CrIII, NiII, ZnII, CuII] and comparison with a previously reported analogue without the cyclohexane rings, trans-13-amino-13-methyl-1,4,8,11-tetraazacyclotetradecane-6-carboxylic acid (2a) salt, is described. The [Ni{(1a) – H+}](ClO4) crystallizes in the monoclinic space group P21, a 9.710(2), b 14.442(1), c 10.317(2) Å, β 96.02(2)°. The nickel displays a distorted octahedral geometry, with all four secondary amines coordinated (Ni–N range 2.044(7)–2.063(6) Å), in addition to pendant primary amine (Ni–N, 2.109(6) Å) and carboxylate (Ni–O, 2.100(6) Å) groups. Protonation constants for the trans (1a) and cis (1b) isomers and stability constants of these isomers with the labile metal ions ZnII, CdII, HgII, PbII, MnII, and CoII were determined by potentiometric titrations. The log K values for 1 : 1 complexes show small variations between geometric isomers.

scholarly journals Crystal structure and Hirshfeld surface analysis of bis(benzoato-κ2 O,O′)[bis(pyridin-2-yl-κN)amine]nickel(II)

2019 ◽  
Vol 75 (9) ◽  
pp. 1301-1305
Author(s):  
Phichitra Phiokliang ◽  
Phakamat Promwit ◽  
Kittipong Chainok ◽  
Nanthawat Wannarit
Keyword(s):  
Surface Analysis ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Distorted Octahedral Geometry ◽  
Monoclinic Space Group ◽  
Complex Molecules ◽  
One Dimensional ◽  
Centroid Distance ◽  
Distorted Octahedral

A new mononuclear NiII complex with bis(pyridin-2-yl)amine (dpyam) and benzoate (benz), [Ni(C7H5O2)2(C10H9N3)], crystallizes in the monoclinic space group P21/c. The NiII ion adopts a cis-distorted octahedral geometry with an [NiN2O4] chromophore. In the crystal, the complex molecules are linked together into a one-dimensional chain by symmetry-related π–π stacking interactions [centroid-to-centroid distance = 3.7257 (17) Å], along with N—H...O and C—H...O hydrogen bonds. The crystal packing is further stabilized by C—H...π interactions, which were investigated by Hirshfeld surface analysis.

Structure and Fluorescence Properties of a Novel Supramolecular Zinc Complex

2008 ◽  
Vol 63 (12) ◽  
pp. 1357-1360 ◽  
Author(s):  
Gang Chen
Keyword(s):  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Free Ligand ◽  
Distorted Octahedral Geometry ◽  
Monoclinic Space Group ◽  
Ligand Complex ◽  
Complex Molecules ◽  
Hydrogen Bonding Interactions ◽  
Distorted Octahedral ◽  
Cell Dimensions

Hydrothermal reaction of Zn(NO3)2 · 6H2O and 2-hydroxypyridine-3-carboxylic acid afforded a novel supramolecular complex, [Zn(C6H4NO3)2(H2O)2] (1). The complex has been characterized by macroanalysis, IR spectra, and thermogravimetric and differential thermal analysis (TG/DTA). Single crystal X-ray analysis shows that complex 1 crystallizes in the monoclinic space group P21/c with the cell dimensions a = 7.534(6), b = 12.289(1), c = 7.534(6) Å, β = 100.51°, V = 685.85(1) Å3, and Z = 2. The six-coordinated Zn atom is in a severely distorted octahedral geometry. The complex molecules are assembled via strong O-H· · ·O and N-H· · ·O hydrogen bonding interactions into a three-dimensional supramolecular framework. Compared with the free ligand, complex 1 exhibits strong fluorescence in the solid state at room temperature.

Synthesis and Structure of cis-Dioxobis(pyrimidine-2-thiolato-N,S)molybdenum(VI)

1992 ◽  
Vol 45 (11) ◽  
pp. 1933 ◽  
Author(s):  
PR Traill ◽  
AG Wedd ◽  
ERT Tiekink
Keyword(s):  
Least Squares ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
Distorted Octahedral ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The characterization of two MoVI complexes, cis -[MoO2(2-pymS)2] and cis -[MoO2(2-pyS)2] (where 2-pymSH is pyrimidine-2-thiol and 2-pySH is pyridine-2-thiol), and their reaction with Ph3P are reported. The X-ray structure of cis -[MoO2(2-pymS)2] shows the molybdenum atom to exist in a distorted octahedral geometry defined by two mutually cis oxygen atoms and two chelating 2-pymS ligands so that the two sulfur atoms occupy approximate trans positions. Crystals of cis -[MoO2(2-pymS)2] are monoclinic, space group P 21/n, with unit cell dimensions: a 9.301(3), b 12.121(2), c 11.303(3) �, β 112.62(3)�, V 1176.3 �3, Z 4. The structure was refined by a full-matrix least-squares procedure to R 0.067 for 1858 reflections with I ≥ 2.5 (I).

Quinquedentate Coordination of 3-[(2'-Amino-ethyl)amino]-2-[(2″-aminoethyl)aminomethyl]propionic Acid (LH). Crystal Structure of trans-[Co(L)Cl][ClO4].H2O And Molecular Mechanics Examination of Isomers

1994 ◽  
Vol 47 (5) ◽  
pp. 817 ◽  
Author(s):  
PV Bernhardt ◽  
TW Hambley ◽  
GA Lawrance ◽  
KJ Molloy
Keyword(s):  
Crystal Structure ◽  
Molecular Mechanics ◽  
Propionic Acid ◽  
Structure Determination ◽  
Strain Energy ◽  
Secondary Amines ◽  
Primary Amines ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Polyamino Acid

The anion (1c) of the branched polyamino acid 3-[(2′-aminoethyl)amino]-2-[(2″-aminoethyl)- aminomethyl ] propionic acid (1b) binds as a quinquedentate ligand to cobalt(III). Reaction with cobalt(II) chloride, followed by oxidation and acidification, yields exclusively one isomer of [Co(1c) Cl ]+. The complex was crystallized readily as a perchlorate monohydrate salt, in the monoclinic space group P 21/n, a 7.921(2), b 17.357(4), c 11.852(4) Ǻ, β 107.25(2)°, Z = 4; a single-crystal X-ray structure determination was refined to R 0.033 for 2099 `observed' reflections. The carboxylate and two adjacent secondary amines occupy an octahedral face, with the chloro ligand trans to the carboxylate , and the secondary amines adopt R,S stereochemistries. The Co-O distance [1.901(2) Ǻ] is at the short end of the range of cobalt- carboxylate bonds, and Co-N distances [average 1.944 Ǻ (primary amines), average 1.950 Ǻ (secondary amines)] are slightly shorter than average for Co-N bonds. The Co- Cl distance is 2.255(1) Ǻ. Molecular mechanics examination of all possible isomers and conformers of [Co(1c) Cl ]+ and of the related pentaamine 1,5,9-triamino-5-methyl-3,7-diazanonane (2) indicate a greater variation in strain energy across the range of isomers and conformers in the latter more strained system.

scholarly journals The first structural characterization of the protonated azacyclam ligand in catena-poly[[[(perchlorato)copper(II)]-μ-3-(3-carboxypropyl)-1,5,8,12-tetraaza-3-azoniacyclotetradecane] bis(perchlorate)]

2019 ◽  
Vol 75 (11) ◽  
pp. 1700-1704
Author(s):  
Liudmyla V. Tsymbal ◽  
Vladimir B. Arion ◽  
Yaroslaw D. Lampeka
Keyword(s):  
Carboxylic Acid ◽  
Metal Ion ◽  
Macrocyclic Ligand ◽  
Acid Group ◽  
Distorted Octahedral Geometry ◽  
Equatorial Orientation ◽  
Carboxylic Acid Group ◽  
Bond Lengths ◽  
Distorted Octahedral

The asymmetric unit of the title compound, catena-poly[[[(perchlorato-κO)copper(II)]-μ-3-(3-carboxypropyl)-1,5,8,12-tetraaza-3-azoniacyclotetradecane-κ4 N 1,N 5,N 8,N 12] bis(perchlorate)], {[Cu(C13H30N5O2)(ClO4)](ClO4)2} n , (I), consists of a macrocyclic cation, one coordinated perchlorate anion and two perchlorate ions as counter-anions. The metal ion is coordinated in a tetragonally distorted octahedral geometry by the four secondary N atoms of the macrocyclic ligand, the mutually trans O atoms of the perchlorate anion and the carbonyl O atom of the protonated carboxylic acid group of a neighbouring cation. The average equatorial Cu—N bond lengths [2.01 (6) Å] are significantly shorter than the axial Cu—O bond lengths [2.379 (8) Å for carboxylate and average 2.62 (7) Å for disordered perchlorate]. The coordinated macrocyclic ligand in (I) adopts the most energetically favourable trans-III conformation with an equatorial orientation of the substituent at the protonated distal 3-position N atom in a six-membered chelate ring. The coordination of the carboxylic acid group of the cation to a neighbouring complex unit results in the formation of infinite chains running along the b-axis direction, which are crosslinked by N—H...O hydrogen bonds between the secondary amine groups of the macrocycle and O atoms of the perchlorate counter-anions to form sheets lying parallel to the (001) plane. Additionally, the extended structure of (I) is consolidated by numerous intra- and interchain C—H...O contacts.

Syntheses and Comparative Base Hydrolysis Reactions of Chlorocobalt(III) Complexes of Pendant-Arm Macrocyclic Polyamines and Polyamino Acids

1997 ◽  
Vol 50 (9) ◽  
pp. 883 ◽  
Author(s):  
Yakup Baran ◽  
Trevor W. Hambley ◽  
Geoffrey A. Lawrance ◽  
Eric N. Wilkes
Keyword(s):  
Water Molecule ◽  
Activation Enthalpy ◽  
Base Hydrolysis ◽  
Secondary Amines ◽  
Methyl Groups ◽  
Monoclinic Space Group ◽  
Carboxylate Group ◽  
Hydrolysis Kinetics ◽  
Pendant Arm ◽  
Macrocyclic Polyamines

Chlorocobalt(III) complexes of the pendant-arm macrocycles 1,4,8,12-tetraazacyclopentadecane-10-carboxylate (2) and 1,5,9,13-tetraazabicyclo[11.2.2]heptadecane-7-carboxylate (4) have been prepared to complement the known complexes of 10-methyl-1,4,8,12-tetraazacyclopentadecan-10-amine (1) and 7-methyl-1,5,9,13-tetraazabicyclo[11.2.2]heptadecan-7-amine (3). The pairs (1),(3) and (2),(4) differ in replacement of pendant amine and methyl groups in the former pair by a pendant carboxylate group and hydrogen in the latter pair. The macromonocyclic ligands (1) and (2) form cis-chlorocobalt(III) complexes whereas the macrobicyclic ligands (3) and (4) (which contain an additional –CH2–CH2– ‘strap’ linking two amines) form trans-chlorocobalt(III) complexes, defined in terms of location of the pendant donor and the chloride donor. Chloride base hydrolysis kinetics varies with ligand {cis-[Co(1)Cl]2+, kOH 6700 dm3 mol-1 s-1 ; cis-[Co(2)Cl] +, kOH 1800 dm3 mol-1 s-1;trans-[Co(3)Cl]2+, kOH 3450 dm3 mol-1 s-1; trans-[Co(4)Cl]+, kOH 2250 dm3 mol-1 s-1 at 25°C}. Variations in rate constant are tied mainly to variations in activation enthalpy. Chloride hydrolyses occur with retention of configuration, but slow following isomerization can lead to products such as trans-[Co(2)(OH2)] (ClO4)2.2H2O, which crystallizes in the monoclinic space group P21/c, a 9·581(2), b 16·214(2), c 14·350(2) Å and β 94·66(1)°. The pendant carboxylate group and two adjacent secondary amines necessarily occupy an octahedral face, with the water molecule bound trans to the pendant carboxylate. The four Co–N distances range from 1·981(2) to 2·22(3) Å, and along with carboxylate Co–O (1·882(3) Å) and water Co-O (1·934(2) Å) distances are similar to usual distances in cobalt(III) complexes.

The Crystal Structures of [N,N’-Bis(3-methoxysalicylidene)-1,3- diaminopropane]nickel(II) and -copper(II)

2004 ◽  
Vol 59 (2) ◽  
pp. 228-232 ◽  
Author(s):  
Ayhan Elmali ◽  
Celal T Zeyrek ◽  
Yalcin Elerman
Keyword(s):  
Crystal Structures ◽  
Mirror Symmetry ◽  
Distorted Octahedral Geometry ◽  
Planar Geometry ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Bond Lengths ◽  
Distorted Octahedral

[N,N′’-Bis(3-methoxysalicylidene)-1,3-diaminopropane]nickel(II) dihydrate [Ni(C19H20N2O4)· 2(H2O)] 1 and [N,N′-bis(3-methoxysalicylidene)-1,4-diaminobutane]copper(II) [Cu(C20H22N2O4)] 2 have been synthesized and their crystal structures determined. Crystals of compound 1 are orthorhombic, space group Pnma, a = 7.509(3), b = 22.070(7), c = 11.532(4) Å, V = 1611.1(12) Å3, Z = 4 and Dc = 1.498 g·cm−3. The molecule 1 has mirror symmetry, but the ligand is not planar. The two parts of the Schiff base moieties are folded so as to form an angle of 21.6(1)°. The Ni atom is in a distorted octahedral geometry and coordinated by the donor atoms of the ligand in the horizontal plane and of two water molecules. Crystals of compound 2 are monoclinic, space group P21/c, a = 9.488(1), b = 21.918(3), c = 8.413(1) Å, β = 91.45(1)°, V = 1749.0(4) Å3, Z = 4 and Dc = 1.587 g·cm−3. The Cu atom is coordinated by an N2O2 donor set from the imine-phenol ligand in a distorted planar geometry, with the two phenolate O atoms deprotonated. The Cu-O bond lengths are 1.854(3) and 1.868(3)Å . The Cu-N bond lengths are 1.931(3) and 1.950(3) Å, the dihedral angle between the two 3-methoxysalicylidene groups is 43.4(1)°.

Synthesis and Crystal Structure of a New Copper(II) Coordination Polymer [CuC16 H18 N4O4S]n*

2012 ◽  
Vol 554-556 ◽  
pp. 268-272
Author(s):  
Jia Gui Li ◽  
Wan Ren Zhu ◽  
Shu Hong Ding ◽  
Yuan Chen ◽  
Yu Lin Zhu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Chain Structure ◽  
Distorted Octahedral Geometry ◽  
Polymeric Chain ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
One Dimensional ◽  
Cell Parameters ◽  
Distorted Octahedral

A new one-dimensional [CuC16H18N4O4S]n(1) was synthesized by the self-assembly of a ligand 2,5-thiophenediformates, 3,5-dimethylpyrazole and copper(II), and characterized by elemental analysis, IR and single-crystal X-ray diffraction. 1 crystallizes in monoclinic, space group C2/c with unit cell parameters, a=18.6156(4), b=5.96110(10), c= 18.1598(4)Å, =115.467(2)°, Z=4, V=1819.37(7)Å3, Mr = 425.94, Dc = 1.555g/cm3, μ=1.345mm-1, and F(000)= 876. The final R and wR are 0.0328 and 0.0816 for 7611 observed reflections with I>2σ(I). 1 shows an infinite 1-D polymeric chain structure based on the repeated basic units Cu(II)(3,5-dimethylpyrazole)2(2,5-thiophene diformate). The Cu(II)center acts as the joint of the unit, and is coordinated in a slightly distorted octahedral geometry comprised of four O atoms from two different 2,5-thiophenediformate ligands and two N atoms of two trans 3,5-dimethylpyrazole ligands.

Cationic iron(III) complex with a hexadentate N2,N'2',O2-aminopyridylphenolate ligand

1999 ◽  
Vol 77 (12) ◽  
pp. 2033-2038 ◽  
Author(s):  
Ika A Setyawati ◽  
Steven J Rettig ◽  
Chris Orvig
Keyword(s):  
Heavy Atom ◽  
Crystallographic Analysis ◽  
Octahedral Geometry ◽  
Distorted Octahedral Geometry ◽  
Monoclinic Space Group ◽  
Cyclic Voltammogram ◽  
X Ray ◽  
R Factor ◽  
Distorted Octahedral ◽  
Elemental Analyses

Iron(III) complexation with potentially hexadentate H2bbpen (N,N'-bis(2-hydroxybenzyl)-N,N'-bis(2-methylpyridyl)ethylenediamine) was studied. The resulting monocationic complex, [Fe(bbpen)]+ as its NO3- and PF6- salts, was characterized by infrared spectroscopy, mass spectrometry, elemental analyses, cyclic voltammetry, and X-ray crystallographic analysis. Crystals of [Fe(bbpen)]NO3·CH3OH are monoclinic, space group P21/c, a = 10.2640(13), b = 14.7526(10), c = 18.3172(5) Å, β = 97.904(1)°, and Z = 4. The structure was solved by heavy-atom Patterson methods and refined to an R factor of 0.039 for 3526 reflections with I > 3σ(I). The structure of the [Fe(bbpen)]+ cation showed that the ligand is bound in a hexadentate fashion to the central Fe(III) ion, resulting in a distorted octahedral geometry. Magnetic susceptibility measurements indicated the presence of a high-spin Fe(III) ion, and the UV-vis spectrum of [Fe(bbpen)]NO3 exhibits absorption maxima, λmax, at 575 nm (ε = 5400 M-1 cm-1), 323 (8900), and 275 (13 500). The cyclic voltammogram of [Fe(bbpen)]NO3 showed a quasi-reversible, one-electron process corresponding to [FeIII(bbpen)]+ + e- <_> [FeII(bbpen)] at -0.47 V vs. SCE.Key words: cationic, iron(III), phenolate, pyridyl, hexadentate.

scholarly journals A Novel Tris(2-aminoethyl)amine Based Tripodal Ligand: Synthesis and Solution Coordination Studies with Trivalent Iron and Chromium

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Minati Baral ◽  
Amit Gupta ◽  
Rifat Akbar ◽  
Bikram K. Kanungo
Keyword(s):  
Metal Ions ◽  
Formation Constants ◽  
Distorted Octahedral Geometry ◽  
Trivalent Metal ◽  
Tripodal Ligand ◽  
Complex Species ◽  
Distorted Octahedral ◽  
Coordination Behaviour ◽  
Trivalent Metal Ions ◽  
Ph Range

A novel tris(2-aminoethyl)amine (TREN) based tripodal ligand TRENOL (L) has been synthesized and characterized by elemental analysis and UV-VIS, IR, 1H, and 13C NMR spectroscopic methods. The coordination behaviour of the ligand with H+ and trivalent metal ions, Fe(III) and Cr(III), was investigated in aqueous medium at 0.1 M KCl at 25±1°C by potentiometric and spectrophotometric studies. Tripodal ligand showed seven protonation constants in the adopted pH range 2–11 and its electronic spectra exhibited three bands at 216, 323, and 423 nm. Ligand formed various metal complex species of the type MLH5, MLH4, MLH3, MLH, and ML with trivalent metal ions. The determined values of the formation constants (for ML species) of the ligand with Fe(III) and Cr(III) were 24.19 and 18.64, respectively. Molecular modeling studies revealed that the metal complexes formed distorted octahedral geometry. Besides, ligand showed fluorescence at 496 nm when excited at 289 nm. The fluorescence behaviour of the ligand in the presence of Fe(III) ions showed noticeable quenching in comparison to the other metal ions at physiological pH (7.4). So, as per the outcomes of the present study, TRENOL has the potential to be used as the iron detector in environmental, agricultural, and medical fields.

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