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The crystal structure of the new double CuII complex salt, [Cu(L)(H2O)2][Cu(L)]Br4·2H2O (L = 3,14-diethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane, C22H44N4) has been determined using synchrotron radiation. The asymmetric unit contains one half of a [Cu(L)(H2O)2]2+ cation, one half of a [Cu(L)]2+ cation (both completed by crystallographic inversion symmetry), two bromide anions and one water solvent molecule. The CuII atom in the first complex exists in a tetragonally distorted octahedral environment with the four N atoms of the macrocyclic ligand in equatorial and two aqua ligands in axial positions, whereas the CuII atom in the second complex exists in a square-planar environment defined by the four nitrogen atoms of the macrocyclic ligand. The two macrocyclic rings adopt the most stable trans-III configuration with normal Cu—N bond lengths from 2.016 (3) to 2.055 (3) Å and an axial Cu—O bond length of 2.658 (4) Å. The crystal structure is stabilized by intermolecular hydrogen bonds involving the macrocycle N—H or C—H groups and the O—H groups of water molecules as donor groups, and the O atoms of water molecules and bromide anions as acceptor groups, giving rise to a one-dimensional network extending parallel to [100].

The crystal structure of title salt, C22H46N42+·2NO3−·2H2O, has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at diagonally opposite amine N atoms. The asymmetric unit contains half a centrosymmetric dication, one nitrate anion and one water molecule. The molecular dication, C22H46N42+, together with the nitrate anion and hydrate water molecule are involved in an extensive range of hydrogen bonds. The molecule is stabilized, as is the conformation of the dication, by forming intermolecular N—H...O, O—H...O, together with intramolecular N—H...N hydrogen bonds.

The asymmetric unit of the title compound, Ag[Cr(C11H14N2O8)]·3H2O, contains one [Cr(1,3-pdta)]− anion [1,3-pdta is (propane-1,3-diyldinitrilo)tetraacetate], one Ag+ cation and three water molecules. The Cr3+ ion is coordinated to the four O and two N atoms of the 1,3-pdta ligand, displaying a distorted octahedral geometry. The mean Cr—N and Cr—O bond lengths are 2.0727 (17) and 1.9608 (15) Å, respectively. The conformations of the chelate rings were found to be envelope for the glycinates and twist-boat for the six-membered diamine (T) ring. The Ag+ cation is surrounded by six O atoms from three non-coordinated carbonyl O atoms of neighbouring 1,3-pdta groups and three water molecules. The crystal structure is stabilized by intermolecular hydrogen bonding involving the water O—H group as donor and the carboxyl O atom as acceptor.

The structure of the title compound, [CrCl2(tn)2]2[Cr2O7] (tn = propane-1,3-diamine; C3H10N2), has been determined from synchrotron data. The asymmetric unit contains one CrIII complex cation and half a [Cr2O7]2− anion. In the complex cation, the CrIII ion is coordinated by the four N atoms of two propane-1,3-diamine (tn) ligands in the equatorial plane and by two Cl atoms in a trans configuration, displaying a distorted octahedral coordination sphere. The two six-membered rings in the complex cation have an anti chair–chair conformation with respect to each other. The mean Cr—N(tn) and Cr—Cl bond lengths are 2.09 (1) and 2.320 (2) Å, respectively. The slightly bent dichromate anion is disordered over two sets of sites (occupancy ratio = 0.7:0.3) and has a staggered conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the NH2 groups of the tn ligands as donors and the O atoms of the [Cr2O7]2− anion and chlorido ligands as acceptors.

The structure of the title compound, [Cr(NCS)2(cyclam)]2[ZnCl4] (cyclam = 1,4,8,11-tetraazacyclotetradecane, C10H24N4), has been determined from synchrotron data. The asymmetric unit contains two independent halves of the CrIII complex cations and half of a tetrachloridozincate anion. In each complex cation, the CrIII atom is coordinated by the four N atoms of the cyclam ligand in the equatorial plane and by two N-bound NCS− anions in a trans axial arrangement, displaying a distorted octahedral geometry with crystallographic inversion symmetry. The mean Cr—N(cyclam) and Cr—N(NCS) bond lengths are 2.065 (4) and 1.995 (6) Å, respectively. The macrocyclic cyclam moieties adopt centrosymmetric trans-III configurations with six- and five-membered chelate rings in chair and gauche configurations, respectively. The [ZnCl4]2− anion, which lies about a twofold rotation axis, has a slightly distorted tetrahedral geometry. The crystal packing is stabilized by hydrogen-bonding interactions between the N—H groups of the cyclam ligands, the S atoms of the NCS− groups and the Cl− ligands of the anion.

The structure of the title salt, [CrCl(C10H8N2)2(H2O)][ZnCl4], has been determined from synchrotron data. The CrIII ion is coordinated by four N atoms from two 2,2′-bipyridine (bipy) ligands, one O atom from a water molecule and a chloride anion in a cis arrangement, displaying a distorted octahedral geometry. The tetrahedral [ZnCl4]2− anion is slightly distorted owing to its involvement in O—H...Cl hydrogen bonding with the coordinating water molecule. The Cr—N(bipy) bond lengths are in the range 2.0485 (13)–2.0632 (12) Å, while the Cr—Cl and Cr—(OH2) bond lengths are 2.2732 (6) and 1.9876 (12) Å, respectively. In the crystal, molecules are stacked along the a axis.

The title salt, Na[CrF2(C5H5N)4]2[ZnCl4]ClO4, consists of two cationic CrIII complexes, an Na+ cation, one [ZnCl4]2− anion and one ClO4− anion. The CrIII atoms are coordinated by four pyridine (py) N atoms and two F atoms in a trans arrangement, displaying a distorted octahedral geometry. The mean Cr—N(py) and Cr—F bond lengths are 2.086 (8) and 1.864 (14) Å, respectively. The [ZnCl4]2− anion has a distorted tetrahedral geometry. The most notable feature of the crystal packing is the formation of weak pyridine–perchlorate C—H...O hydrogen bonds, resulting in supramolecular chains along the b-axis direction. The perchlorate anion was disordered over two sets of sites in a 0.868 (3):0.132 (3) ratio.

The crystal structure of [Cr(NCS)2(cyclam)]NCS (cyclam = 1,4,8,11-tetraazacyclotetradecane, C10H24N4) has been determined by using synchrotron radiation at 98 K. The CrIII atom is in a slightly distorted octahedral environment with four N atoms of the macrocyclic ligand and two N-coordinated NCS− anions in cis positions. The average Cr—N(cyclam) and Cr—NCS bond lengths are 2.085 (5) and 1.996 (15) Å, respectively. In the crystal, the uncoordinating SCN− anion is hydrogen bonded through N—H...S and N—H...N interactions to neighbouring complex cations.

In the title co-crystal, C20H40N4·2C11H10O, the macrocycle is generated by a crystallographic inversion centre. The N atoms show a pyramidal coordination, and the cyclohexane ring that is fused to the 14-membered C10N4 ring exists in a chair conformation, whereas the methyl substituent occupies an axial site. The (naphthalen-1-yl)methanol molecule forms an O—H...N hydrogen bond to a cyclam N atom. The mean-square-plane passing through the 14-membered ring is approximately coplanar with the naphthalene fused-ring [dihedral angle = 6.6 (1)°].

The crystal structure of the new double CuII complex salt, [Cu(L)(H2O)2][Cu(L)]Br4·2H2O (L = 3,14-diethyl-2,6,13,17-tetra­aza­tri­cyclo­[16.4.0.07,12]docosane, C22H44N4) has been determined using synchrotron radiation. The asymmetric unit contains one half of a [Cu(L)(H2O)2]2+ cation, one half of a [Cu(L)]2+ cation (both completed by crystallographic inversion symmetry), two bromide anions and one water solvent mol­ecule. The CuII atom in the first complex exists in a tetra­gonally distorted octa­hedral environment with the four N atoms of the macrocyclic ligand in equatorial and two aqua ligands in axial positions, whereas the CuII atom in the second complex exists in a square-planar environment defined by the four nitro­gen atoms of the macrocyclic ligand. The two macrocyclic rings adopt the most stable trans-III configuration with normal Cu—N bond lengths from 2.016 (3) to 2.055 (3) Å and an axial Cu—O bond length of 2.658 (4) Å. The crystal structure is stabilized by inter­molecular hydrogen bonds involving the macrocycle N—H or C—H groups and the O—H groups of water mol­ecules as donor groups, and the O atoms of water mol­ecules and bromide anions as acceptor groups, giving rise to a one-dimensional network extending parallel to [100]. [ABSTRACT FROM AUTHOR]

The crystal structure of title salt, C22H46N42+·2NO3−·2H2O, has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at diagonally opposite amine N atoms. The asymmetric unit contains half a centrosymmetric dication, one nitrate anion and one water mol­ecule. The mol­ecular dication, C22H46N42+, together with the nitrate anion and hydrate water mol­ecule are involved in an extensive range of hydrogen bonds. The mol­ecule is stabilized, as is the conformation of the dication, by forming inter­molecular N—H⋯O, O—H⋯O, together with intra­molecular N—H⋯N hydrogen bonds. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, Ag[Cr(C11H14N2O8)]·3H2O, contains one [Cr(1,3-pdta)]- anion [1,3-pdta is (propane-1,3-diyldinitrilo)tetraacetate], one Ag+ cation and three water molecules. The Cr3+ ion is coordinated to the four O and two N atoms of the 1,3-pdta ligand, displaying a distorted octahedral geometry. The mean Cr--N and Cr--O bond lengths are 2.0727 (17) and 1.9608 (15) Å, respectively. The conformations of the chelate rings were found to be envelope for the glycinates and twist-boat for the six-membered diamine (T) ring. The Ag+ cation is surrounded by six O atoms from three noncoordinated carbonyl O atoms of neighbouring 1,3-pdta groups and three water molecules. The crystal structure is stabilized by intermolecular hydrogen bonding involving the water O--H group as donor and the carboxyl O atom as acceptor. [ABSTRACT FROM AUTHOR]

The structure of the title compound, [CrCl2(tn)2]2[Cr2O7] (tn = propane-1,3-diamine; C3H10N2), has been determined from synchrotron data. The asymmetric unit contains one CrIII complex cation and half a [Cr2O7]2- anion. In the complex cation, the CrIII ion is coordinated by the four N atoms of two propane-1,3-diamine (tn) ligands in the equatorial plane and by two Cl atoms in a trans configuration, displaying a distorted octahedral coordination sphere. The two six-membered rings in the complex cation have an anti chair-chair conformation with respect to each other. The mean Cr-N(tn) and Cr-Cl bond lengths are 2.09 (1) and 2.320 (2) Å, respectively. The slightly bent dichromate anion is disordered over two sets of sites (occupancy ratio = 0.7:0.3) and has a staggered conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the NH2 groups of the tn ligands as donors and the O atoms of the [Cr2O7]2- anion and chlorido ligands as acceptors. [ABSTRACT FROM AUTHOR]

The structure of the title salt, [CrCl(C10H8N2)2(H2O)][ZnCl4], has been determined from synchrotron data. The CrIII ion is coordinated by four N atoms from two 2,2'-bipyridine (bipy) ligands, one O atom from a water molecule and a chloride anion in a cis arrangement, displaying a distorted octahedral geometry. The tetrahedral [ZnCl4]2- anion is slightly distorted owing to its involvement in O-H···Cl hydrogen bonding with the coordinating water molecule. The Cr-N(bipy) bond lengths are in the range 2.0485 (13)-2.0632 (12) Å , while the Cr-Cl and Cr-OH2) bond lengths are 2.2732 (6) and 1.9876 (12) Å, respectively. In the crystal, molecules are stacked along the a axis. [ABSTRACT FROM AUTHOR]

The article reports the synthesis, crystal structure and spectroscopic properties of the trans-anti [CR(Me,2tn)2(OH)(H2O)]-CIO4)2 to elucidate the influence of O-donor ligands occupying the axial positions and counter anion. It shows that chromium atom is in a distorted octahedral environment coordinated by 2 biidetate, 2,2-dimethyl-1,3-propanediamine ligands and 2 O atoms of hydroxy group and water molecule in trans position.

The aim of the present study is to explore the possibility of utilizing loess for the adsorption of total phosphorous (T-P) and total nitrogen (T-N) in water. Batch adsorption studies were performed to evaluate the influences of various factors like initial concentration, contact time and temperature on the adsorption of T-P and T-N. The adsorption data showed that loess is not effective for the adsorption of T-N. However, loess exhibited much higher adsorption capacity for T-P. At concentration of 1.0 mg L-1, approximately 97% of T-P adsorption was achieved by loess. The equilibrium data were fitted well to the Langmuir isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher R² compared with the pseudo-first-order and intra-particle kinetic model. The theoretical adsorption equilibrium qe,cal from pseudo-second-order kinetic model was relatively similar to the experimental adsorption equilibrium qe,exp. The thermodynamic parameters such as free energy ρG, the enthalpy ρH and the entropy ρS were also calculated. [ABSTRACT FROM AUTHOR]

In the title compound, [Cu(ClO4)2(C20H40N4)], the CuII ion has a tetragonally distorted octahedral environment, with the four N atoms of the macrocyclic ligand in equatorial positions and the O atoms of two perchlorate groups in axial positions. The CuII ion is situated on an inversion centre. The macrocyclic ligand adopts its most stable trans-III conformation. The long axial Cu—O bond is the result of the Jahn–Teller effect. The crystal structure is stabilized by intramolecular hydrogen bonds between secondary N—H and the O atoms of the perchlorate groups. [ABSTRACT FROM AUTHOR]