Synthesis, Crystal Structure, Hirshfeld Surface Analysis, and Computational Study of a Novel Organic Salt Obtained from Benzylamine and an Acidic Component.

A novel Schiff base compound named as phenylmethanaminium (E)-4-((benzylimino)methyl)benzoate C7H10N+. C15H12NO2 - (A) is synthesized by the chemical reaction of benzylamine and 4-carboxybenzaldehyde in ethanol, and the structure of the titled compound is verified using the single-crystal X-ray diffraction technique. Structural investigation inferred that the crystal packing is mainly stabilized by N-H···O and comparatively weak C-H···O bonding between the cation and anion and further stabilized by weak C-H···π and C-O···π interactions. Hirshfeld surface analysis is employed to explore the noncovalent interactions that are responsible for crystal packing quantitatively. Furthermore, we have used state-of-the-art quantum chemical calculations to get comprehensive insights into the structure-optoelectronic property relationship for the entitled compound. The molecular geometry of compound A is optimized at the M06/6-311G* level of theory. The linear polarizability, third-order nonlinear optical (NLO) polarizability, total and partial density of states, and UV-visible spectrum are calculated through quantum chemical calculations. We believe that compound A is not only a new addition to crystallographic data but also possesses good optical and NLO properties for its potential use in lasers and frequency-converting applications.

Cis-dioxo-bis [3-methoxy-2,2-dimethylpropanediamine] Molybdenum/Surfactant-Modified Electrode for Simultaneous Sensing of Ascorbic Acid and Dopamine.

In this work, the carbon paste electrode (CPE) was modified using the cis-dioxo-bis[3-methoxy-2,2-dimethylpropanediamine] molybdenum(VI) complex and 1-octanaminium,N,N,N-trioctyl bromide. Using the modified electrode, the best separation of anodic peaks for ascorbic acid and dopamine was obtained in solutions with pH 5.0 and the linear range for ascorbic acid is acquired in the range from 3.0 × 10-6 to 6.0 × 10-3 M and for dopamine from 2.0 × 10-6 to 1.0 × 10-2 M. The limits of detection (S/N = 3) were 4 × 10-7 M and 5 × 10-7 M for dopamine and ascorbic acid, respectively. Surface regeneration and the very easy preparation of the modified CPE together with the very good peak resolution and sub-micromolar detection limits designate the prepared carbon paste electrode appropriate for simultaneous voltammetric determination of dopamine and ascorbic acid.

{4,4',6,6'-Tetrachloro-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}dioxidomolyb-denum(VI).

The asymmetric unit of the title compound, [Mo(C(19)H(16)Cl(4)N(2)O(2))O(2)], comprises two independent mol-ecules (A and B). The geometry around the Mo(VI) atom is distorted octa-hedral in each complex mol-ecule, supported by two oxide O atoms and the N(2)O(2) donor atoms of the coordinating ligand. The dihedral angle between the benzene rings is 74.96 (11) Šfor mol-ecule A and 76.05 (11) Šfor mol-ecule B. In the crystal, the B mol-ecules are linked by pairs of C-H⋯Cl hydrogen bonds, forming inversion dimers. The crystal structure is further stabilized by C-H⋯π inter-actions. An inter-esting feature of the crystal structure is a Cl⋯Cl contact [3.3748 (18) Å], which is shorter than the sum of the van der Waals radii of Cl atoms (3.50 Å).

{4,4'-Dimeth-oxy-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}copper(II) monohydrate.

The asymmetric unit of the title compound, [Cu(C(21)H(24)N(2)O(4))]·H(2)O, comprises half of a Schiff base complex and a water mol-ecule. The Cu(II) atom, water mol-ecule and one C atom of the central propyl-ene segment are located on a twofold rotation axis. The geometry around the Cu(II) atom is distorted square-planar, supported by the N(2)O(2) donor atoms of the coordinating ligand. The dihedral angle between the symmetry-related benzene rings is 42.56 (19)°. In the crystal, O-H⋯O hydrogen bonds involving the water mol-ecule make an R(2) (1)(6) ring motif. Complex mol-ecules are linked into a chain along the c axis via C-H⋯O inter-actions.

Dioxido{4,4',6,6'-tetrabromo-2,2'-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}molyb-denum(VI).

The asymmetric unit of the title compound, [Mo(C(19)H(16)Br(4)N(2)O(2))O(2)], comprises two mol-ecules. The coordination environments around the Mo(VI) atoms are distorted octa-hedral, defined by two oxide ligands and an N(2)O(2) donor set of the tetra-dentate Schiff base in each mol-ecule. The dihedral angles between the benzene rings in the mol-ecules are 76.2 (3) and 77.7 (3)°. An inter-esting feature of the crystal structure is the presence of Br⋯Br contacts [3.4407 (11), 3.5430 (11) and 3.6492 (10) Å], which are shorter than the sum of the van der Waals radius of Br atoms (3.70 Å). The crystal structure is further stabilized by inter-molcular C-H⋯Br and C-H⋯π inter-actions. The crystal under investigation was twinned by nonmerohedry in a 0.053 (1):0.947 (1) ratio.

{4,4'-Dimethyl-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}copper(II) monohydrate.

The asymmetric unit of the title compound, [Cu(C(21)H(24)N(2)O(2))]·H(2)O, comprises half of a Schiff base complex and half of a water mol-ecule. The whole compound is generated by crystallographic twofold rotation symmetry. The geometry around the Cu(II) atom, located on a twofold axis, is distorted square-planar, which is supported by the N(2)O(2) donor atoms of the coordinating Schiff base ligand. The dihedral angle between the symmetry-related benzene rings is 47.5 (4)°. In the crystal, the water mol-ecule that is hydrogen bonded to the coordinated O atoms links the mol-ecules via O-H⋯O inter-actions into chains parallel to [001]. The crystal structure is further stabilized by C-H⋯π inter-actions, and by π-π inter-actions involving inversion-related chelate rings [centroid-centroid distance = 3.480 (4) Å].

An ortho-rhom-bic polymorph of 2-(1,3-benzothia-zol-2-yl)-6-eth-oxy-phenol.

In the title mol-ecule, C(15)H(13)NO(2)S, an intra-molecular O-H⋯N hydrogen bond forms an S(6) ring motif. The benzothia-zole ring system and the benzene ring form a dihedral angle of 8.9 (3) Å. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming chains along the b axis. In addition, π-π inter-actions [centroid-centroid distances = 3.772 (4) and 3.879 (4) Å] are observed.

4-Bromo-2-[(E)-(2-{2-[(2-{[(E)-5-bromo-2-hy-droxy-benzyl-idene]amino}-phen-yl)sulfan-yl]ethyl-sulfan-yl}phen-yl)imino-meth-yl]phenol.

The asymmetric unit of the title compound, C(28)H(22)Br(2)N(2)O(2)S(2), comprises half of a Schiff base ligand, the whole mol-ecule being generated by a crystallographic inversion center located at the mid-point of the C-C bond of the central methyl-ene segment. Intra-molecular O-H⋯N and O-H⋯S hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant inter-molecular inter-actions.

{4,4',6,6'-Tetra-iodo-2,2'-[propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato-κ(4)O,N,N',O'}nickel(II).

The asymmetric unit of the title compound, [Ni(C(17)H(12)I(4)N(2)O(2))], comprises half of a Schiff base complex. The Ni(II) and central C atom of the propyl chain are located on a twofold rotation axis. The geometry around the Ni(II) atom is square planar, supported by the N(2)O(2) donor atoms of the coordinated ligand. In the crystal, there are no significant inter-molecular inter-actions present. The crystal studied was a non-merohedral twin with a refined twin component ratio of 0.944 (1):0.056 (1).

{4,4'-Dichloro-2,2'-[2,2-dimethyl-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenolato}copper(II).

In the title Schiff base complex, [Cu(C(19)H(18)Cl(2)N(2)O(2))], the Cu(II) ion is coordinated in a distorted square-planar environment by two N atoms and two O atoms of the tetra-dentate ligand. The dihedral angle between the benzene rings is 36.86 (14)°. In the crystal, mol-ecules are linked into inversion dimers by pairs of weak C-H⋯O hydrogen bonds. In addition, π-π [centroid-centroid distance = 3.7279 (16) Å] and weak C-H⋯π inter-actions are observed.

(E)-4-Amino-N'-(2-hy-droxy-5-meth-oxy-benzyl-idene)benzohydrazide monohydrate.

In the title compound, C(15)H(15)N(3)O(3)·H(2)O, the hydazide Schiff base mol-ecule shows an E conformation around the C=N bond. An intra-molecular O-H⋯N hydrogen bond makes an S(6) ring motif. The dihedral angle between the substituted phenyl rings is 23.40 (11)°. The water mol-ecule mediates linking of neighbouring mol-ecules through O-H⋯(O,O) hydrogen bonds into infinite chains along the a axis, which are further connected together through N-H⋯O hydrogen bonds, forming a two-dimensional network parallel to (001). C-H⋯O inter-actions aso occur.

4,4',6,6'-Tetra-chloro-2,2'-[(1E,1'E)-propane-1,3-diylbis(nitrilo-methanylyl-idene)]diphenol.

The title compound, C(17)H(14)Cl(4)N(2)O(2), is generated by crystallographic twofold symmetry. The two benzene rings are inclined to one another by 80.17 (10)°. There are two intra-molecular O-H⋯N hydrogen bonds, which make S(6) ring motifs. In the crystal, mol-ecules are linked by C-H⋯O and weak C-H⋯Cl inter-actions, forming a three-dimensional network.

4,4',6,6'-Tetra-bromo-2,2'-[(E,E)-ethane-1,2-diylbis(nitrilo-methanylyl-idene)]di-phenol.

The asymmetric unit of the title compound, C(16)H(12)Br(4)N(2)O(2), comprises half of a potential tetra-dentate Schiff base ligand. The whole mol-ecule is generated by an inversion center located in the middle of the C-C bond of the ethyl-ene segment. There are intra-molecular O-H⋯N hydrogen bonds making S(6) ring motifs. In the crystal, no significant inter-molecular inter-actions are observed.

2-[(Z)-(3-{[(Z)-2-Hy-droxy-3,5-diiodo-benzyl-idene]amino}-propyl-imino)-meth-yl]-4,6-diiodo-phenol.

In the title compound, C(17)H(14)I(4)N(2)O(2), there are two intra-molecular O-H⋯N hydrogen bonds, which make S(6) ring motifs. In the crystal, there are no significant inter-molecular inter-actions present.

catena-Poly[{µ(3)-4,4',6,6'-tetra-bromo-2,2'-[butane-1,4-diylbis(nitrilo-methan-ylyl-idene)]diphenolato}{µ(2)-4,4',6,6'-tetra-bromo-2,2'-[butane-1,4-diylbis(nitrilo-methanylyl-idene)]dipheno-lato}dicopper(II)].

The asymmetric unit of the title coordination polymer consists of a dinuclear neutral complex mol-ecule of formula [Cu(2)(C(18)H(14)Br(4)N(2)O(2))(2)](n). One of the Cu(II) ions is coordinated in a distorted square-planar geometry, whereas the other is coordinated in a distorted square-pyramidal geometry, the long apical Cu-O bond [2.885 (4) Å] of the square-pyramidal coordination being provided by a symmetry-related O atom creating a one-dimensional polymer along [010]. π-π stacking inter-actions [centroid-centroid distance = 3.783 (4) Å] and short inter-chain Br⋯Br inter-actions [3.6142 (12)-3.6797 (12) Å] are observed.

{4,4',6,6'-Tetra-iodo-2,2'-[(2,2-dimethyl-propane-1,3-di-yl)bis-(nitrilo-methanylyl-idene)]diphenolato}nickel(II).

The asymmetric unit of the title compound, [Ni(C(19)H(16)I(4)N(2)O(2))], comprises half of a Schiff base complex. The Ni(II) atom is located on a twofold rotation axis which also bis-ects the central C atom of the 2,2-dimethyl-propane group of the ligand. The geometry around the Ni(II) atom is distorted square-planar, with a dihedral angle of 21.7 (3)° between the symmetry-related N/Ni/O coordination planes. The dihedral angle between the symmetry-related benzene rings is 27.9 (3)°. In the crystal, short inter-molecular I⋯I [3.8178 (9) and 3.9013 (10) Å] inter-actions are present.

Aqua{4,4',6,6'-tetrachloro-2,2'-[(2,2-dimethylpropane-1,3-diyl)bis(nitrilomethanylylidene)]diphenolato}zinc.

The asymmetric unit of the title compound, [Zn(C(19)H(16)Cl(4)N(2)O(2))(H(2)O)], comprises two crystallographically independent mol-ecules. The geometry around the Zn(II) atoms is distorted trigonal-bipyramidal, supported by the N(2)O(2) donor atoms of the tetradentate Schiff base and a coordinating water mol-ecule. The dihedral angles between the benzene rings in the two mol-ecules are 34.10 (15) Šand 30.61 (15) Å. In the crystal, neighbouring independent mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, forming dimers with R(2) (2)(6) ring motifs, and by O-H⋯Cl hydrogen bonds. There are short Cl⋯Cl [3.4728 (16), 3.4863 (16), and 3.388 (1) Å] contacts present, and mol-ecules are also linked by C-H⋯O and π-π [centroid-centroid distance = 3.671 (2) Å] inter-actions.

Bis(dimethyl-formamide-κO){4,4',6,6'-tetra-chloro-2,2-[butane-1,4-di-yl(nitrilo-methanylyl-idene)]diphenolato-κ(4)O,N,N',O'}nickel(II).

In the title Schiff base complex, [Ni(C(18)H(14)Cl(4)N(2)O(2))(C(3)H(7)NO)(2)], the geometry around the Ni(II) atom is distorted octa-hedral. It is coordinated by the N(2)O(2) donor atoms of the tetra-dentate Schiff base ligand and the O atoms of two dimethyl-formamide mol-ecules, which are cis to one another. The benzene rings are almost normal to each other [dihedral angle = 88.60 (14)°]. The various intra-molecular C-H⋯O hydrogen bonds make S(5) and S(6) ring motifs. In the crystal, mol-ecules are linked by pairs of weak C-H⋯Cl inter-actions, forming inversion dimers.

catena-Poly[{µ(3)-4,4',6,6'-tetra-chloro-2,2'-[butane-1,4-diylbis(nitrilo-methanyl-yl-idene)]diphenolato}{µ(2)-4,4',6,6'-tetra-chloro-2,2'-[butane-1,4-diylbis(nitrilo-methanylyl-idene)]diphenolato}dicopper(II)].

The asymmetric unit of the title compound, [Cu(2)(C(18)H(14)Cl(4)N(2)O(2))(2)](n), contains two independent Cu(II) ions which are bridged by a pair of 4,4',6,6'-tetra-chloro-2,2'-[butane-1,4-diylbis(nitrilo-methanylyl-idene)]diphenolate ligands, forming a dinuclear unit. One of the Cu(II) ions is coordinated in a distorted square-planar environment and the other is coordinated in a distorted square-pyramidal environment. The long apical Cu-O bond of the square-pyramidal coordinated Cu(II) ion is formed by a symmetry-related O atom, creating a one-dimensional polymer along [010]. In addition, short inter-molecular Cl⋯Cl distances [3.444 (2) Å] and weak π-π inter-actions [centroid-centroid distances = 3.736 (2)-3.875 (3) Å] are observed. The crystal studied was an inversion twin with a refined twin component ratio of 0.60 (1):0.40 (1).

4-Amino-2-hy-droxy-benzohydrazide.

The asymmetric unit of the title compound, C(7)H(9)N(3)O(2), comprises two crystallographically independent mol-ecules (A and B). In each mol-ecule there is an intra-molecular O-H⋯O hydrogen bond making an S(6) ring motif. In the crystal, a pair of N-H⋯N hydrogen bonds link the two mol-ecules (A and B) into a dimer with an R(2) (2)(6) ring motif. The B mol-ecules are linked via pairs of N-H⋯O hydrogen bonds, forming inversion dimers with an R(2) (2)(10) ring motif. The mol-ecules are further linked via other N-H⋯O hydrogen bonds, forming undulating two-dimensional networks lying parallel to the bc plane. These networks are finally linked via N-H⋯O hydrogen bonds, forming a three-dimensional structure.