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The first three compounds based on a {copper–thiocyanate–dabco} combination, namely, (Hdabco)[Cu2(NCS)3] (1), (H2dabco)[Cu(NCS)3] (2), and [Cu(Hdabco)2(NCS)4]∙2dmso (3), where dabco = 1,4-diazabicyclo[2.2.2]octane were synthesized and characterized by single-crystal XRD, elemental analysis, Raman, and partial IR spectroscopy. In copper(I) derivatives, the influence of the charge of the organic cation on the dimensionality of the crystal structure is observed. Thus, in the case of 1, monoprotonated Hdabco+ cations provide the template for the formation of a polymeric anionic 3D framework {[Cu2(NCS)3]−}n, while in the case of 2, diprotonated H2dabco2+ cations together with discrete [Cu(SCN)3]2− anions generate a simple ionic 0D structure with an island-like crystal lattice. The anionic {[Cu2(SCN)3]−}n framework has infinite square channels of 10 × 10 Å size running along the 001 crystallographic direction. In 3, both the Hdabco+ and thiocyanato units behave as terminal monodentate ligands attached to copper(II) centers via N-donor atoms, forming neutral molecular complexes with an elongated (4+2) octahedral environment. The crystallization molecules of dmso are hydrogen bonded to the protonated parts of the coordinated dabco molecules. A series of by-products Cu(SCN)2(dmso)2 (4), (Hdabco)SCN (5), (H2dabco)(SCN)2 (6), and (H2dabco)(SCN)2∙H2O (7) were identified and characterized. [ABSTRACT FROM AUTHOR]

The mol­ecular bis-chelate complex (2-{[(2-hy­droxy­ethyl-κO)amino-κN]meth­yl}-6-meth­oxy­phenolato-κO)(2-{[(2-hy­droxy­eth­yl)imino-κN]meth­yl}-6-meth­oxy­phenolato-κO)copper(II), [Cu(C10H14NO3)(C10H12NO3)] or [Cu(HLim)(HLam); HLim = C10H14NO3; HLam = C10H12NO3, represents the first compound containing a salicyl­idene-2-ethano­lamine type ligand in both imino HLim (Schiff base) and amino HLam (reduced Schiff base) forms that has been structurally characterized on the basis of X-ray data. Two mol­ecules of the monodeprotonated ligands coordinate the CuII ion in an (N,Ophen)-bidentate and an (N,Ophen,Oalc)-tridentate fashion in the case of the imino and amino forms, respectively. The shape of the CuN2O3 coordination polyhedron is a distorted square-pyramid (geometry index τ5 = 0.26). Inter­molecular N—H···O and O—H···O hydrogen bonds, involving H atoms of the amino and hy­droxy­ethyl groups, create a two-dimensional supra­molecular array extending parallel to (010). [ABSTRACT FROM AUTHOR]

The title compound, [Fe(C3H7NO)6][Cd2Cl7], crystallizes in the trigonal space group R3̅ and is assembled from discrete [Fe(DMF)6] 3+ cations (DMF = N,Ndimethylformamide) and [Cd2Cl7] 3- anions. In the cation, the iron(III) atom, located on a special position of 3̅ site symmetry, is coordinated by six oxygen atoms from DMF ligands with all Fe—O distances being equal [2.0072 (16) A˚ ]. A slight distortion of the octahedral environment of the metal comes from the cis O—Fe—O angles deviating from the ideal value of 90 [86.85 (7) and 93.16 (7)] whilst all the trans angles are strictly 180. The central Cl atom of the [Cd2Cl7] 3- anion is also located on a special position of 3̅ site symmetry and bridges two corner sharing, tetrahedrally coordinated CdII atoms. The two Cd atoms and the central Cl atom are colinear. The two sets of terminal chloride ligands on either side of the dumbbell-like anion are rotated relative to each other by 30. In the crystal, the cations and anions, stacked one above the other along the c-axis direction, are held in place principally by electrostatic interactions. There are also C—H...Cl and C—H...O interactions, but these are rather weak. Of the six crystal structures reported to date for ionic salts of [Fe(DMF)6] n+ cations (n = 2, 3), five contain FeII ions. The title compound is the second example of a stable compound containing the [Fe(DMF)6] 3+ cation. The existence of both [Fe(DMF)6] 2+ and [Fe(DMF)6] 3+ cations shows that the DMF ligand coordination sphere can accommodate changes in the charge and spin states of the metal centre. [ABSTRACT FROM AUTHOR]

A new organic-inorganic hybrid salt [L]2[MnCl4] (I) where L+ is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, is built of discrete organic cations and tetrachloridomanganate(II) anions. The L+ cation was formed in situ in the oxidative cyclocondensation of 2-pyridinecarbaldehyde and CH3NH2·HCl in methanol. The structure was refined as a two-component twin using PLATON (Spek, 2020[Spek, A. L. (2020). Acta Cryst. E76, 1-11.]) to de-twin the data. The twin law (-1 0 0 0 - 1 0 0.5 0 1) was applied in the refinement where the twin component fraction refined to 0.155-(1). The compound crystallizes in the space group P21/c with two crystallographically non-equivalent cations in the asymmetric unit, which possess similar structural conformations. The fused pyridinium and imidazolium rings of the cations are virtually coplanar [dihedral angles are 0.89-(18) and 0.78-(17)°]; the pendant pyridyl rings are twisted by 36.83-(14) and 36.14-(13)° with respect to the planes of the remaining atoms of the cations. The tetrahedral MnCl42- anion is slightly distorted with the Mn-Cl distances falling in the range 2.3469-(10)-2.3941-(9)-Å. The distortion value of 0.044 relative to the ideal tetrahedron was obtained by continuous shape measurement (CShM) analysis. In the crystal, the cations and anions form separate stacks propagating along the a-axis direction. The organic cations display weak π-π stacking. The anions, which are stacked identically one above the other, demonstrate loose packing; the minimum Mn...Mn separation in the cation stack is approximately 7.49-Å. The investigation of the fluorescent properties of a powdered sample of (I) showed no emission. X-band EPR data for (I) at 293 and 77-K revealed broad fine structure signals, indicating moderate zero-field splitting. [ABSTRACT FROM AUTHOR]

The new heterometallic complex, aqua-1κO-bis(μ2-2-iminomethyl-6-methoxyphenolato-1κ2O1,O6:2κ2O1,N)bis(thiocyanato-1κN)calcium(II)copper(II), [CaCu(C8H8NO2)2(NCS)2(H2O)], has been synthesized using a one-pot reaction of copper powder, calcium oxide, o-vanillin and ammonium thiocyanate in methanol under ambient conditions. The Schiff base ligand (C8H9NO2) is generated in situ from the condensation of o-vanillin and ammonia, which is released from the initial NH4SCN. The title compound consists of a discrete binuclear molecule with a {Cu(μ-O)2Ca} core, in which the Cu···Ca distance is 3.4275-(6)-Å. The coordination geometries of the four-coordinate copper atom in the [CuN2O2] chromophore and the seven-coordinate calcium atom in the [CaO5N2] chromophore can be described as distorted square planar and pentagonal bipyramidal, respectively. In the crystal, O-H···S hydrogen bonds between the coordinating water molecules and thiocyanate groups form a supramolecular chain with a zigzag-shaped calcium skeleton. [ABSTRACT FROM AUTHOR]

The Schiff base H2L, namely 2‐(3‐methoxysalicylidene‐amino)‐benzyl‐alcohol, 1 and its two pseudo‐polymorphs H2L⋅CH3OH 2 and H2L⋅H2O 3, have been synthesized by the condensation reaction of 2‐aminobenzyl alcohol and o‐vanillin in different solvents. X‐ray crystallographic analysis revealed that the keto‐enol tautomerism of H2L in solid state exists as a complex system of three different enol, keto and zwitterionic forms in equilibrium, dependent on crystal packing forces and the crystallization solvent. The enol, keto and mixed enol‐zwitterionic (roughly 1:1) forms were observed in the crystal structures of 1, 2 and 3, respectively. The crystallographic results are supported by FTIR and DFT calculations. Photophysical properties were determined in acetonitrile solution and solid state and were supported by TD‐DFT studies. [ABSTRACT FROM AUTHOR]

TTF-salicylaldehyde 1 has been prepared by Stille coupling between TTF-SnMe 3 and 5-bromo-salicylaldehyde and characterized by single crystal X-ray structure analysis. A set of S⋯S, π-π and donor–acceptor intermolecular interactions is observed in the solid state architecture of this precursor. Its condensation reaction with 2-ethanolamine provided the chelating electroactive ligand 4-TTF-2-((2-hydroxyethyl)iminomethyl)-phenol 2 (H 2 L 1 ). Reaction with Cu(OAc) 2 in a 2:1 stoichiometry afforded the one-dimensional coordination chain-like polymer [Cu(HL 1 ) 2 ] n 3 for which the solid state structure has been determined. The Cu(II) coordination sphere contains in the equatorial plane a N2O2 motif arising from two chelating imino-phenol units, while the axial positions are occupied by hydroxo ligands from the pendant hydroxy-ethyl arms of top and bottom neighbouring intra-chain complexes with quite larger Cu–O distances indicative of Jahn-Teller elongation. The TTF units form regular stacks within the chains and further interact laterally through short S⋯S contacts. Cyclic voltammetry measurements on ligand 2 and complex 3 indicate excellent electron donating properties of these multifunctional precursors. [ABSTRACT FROM AUTHOR]

The new heterometallic 2D polymer [Cu(en)2Cd(dca)2(SCN)2]n (en=ethylenediamine; dca=dicyanamide, N(CN)2−), the first example of a compound containing the unique mixed-anion Cd(dca)2(SCN)22− fragment, has been prepared from copper powder, cadmium dicyanamide, ammonium thiocyanate and ethylenediamine in methanol solution in air. The polymeric sheets of the compound comprise two different rings – 28-membered [Cu2Cd4(μ1,5-dca)2(μ1,3-NCS)4] macrocycles in which two 12-membered [Cd2(μ1,5-dca)2] rings form sections. [Copyright &y& Elsevier]

Copper powder reacts with cadmium oxide and ammonia acetate in methanol solution of ethylenediamine affording {[Cu(en)2][Cd2(O2CMe)6]}n in which seven-coordinated cadmium atoms are ligated by three bonding modes of acetate groups forming ladder-like anions [Cd2(O2CMe)6]2−n. The cations [Cu(en)2]2+ are located in the lattice and serve as bridges to connect separate anionic polymer chains into a two- dimensional network via hydrogen bonds. [Copyright &y& Elsevier]

Abstract: Three new Cu/Cd mixed-anion solid-state coordination polymers [Cu(en)2Cd(μ-Cl)(μ-O2CMe)Cl(O2CMe)] n (1), [Cu(en)2CdI1.64(O2CMe)2.36] n (2) and [Cu2(en)4Cd2(NCS)6(O2CMe)2] n (3) have been prepared using unactivated copper powder, cadmium acetate, NH4X (X=Cl, I, NCS) and ethylenediamine in non-aqueous solvents, namely dmso, dmf and CH3OH, in the open air. Depending on the nature of the selected counter-anion in the initial ammonium salt, a facile approach to the controlled assembly of 1D or 2D extended networks has been offered. X-ray studies show that 1 and 2 possess 1D helical chain crystal structures, constituting cationic and mixed-ligand anionic Cd(μ-Cl)(μ-O2CMe)Cl(O2CMe)2−, Cd(μ-O2CMe)2I(O2CMe)2− or Cd(μ-I)(μ-O2CMe)I(O2CMe)2− building blocks, conjoining together through the oxygen atoms of chelating bidentate and simultaneously bridging unidentate acetate ligands and also by a bridging chlorine atom (for 1) and by a bridging iodine or oxygen atom of a weakly bidentate acetate group (for 2). In both complexes, distinct hydrogen bonds are present and serve to increase the dimensionality of the compound from one to two. The 2D polymeric sheet of complex 3 consists of a 1D mixed-anion polymer –NCS–Cd(NCS)2(O2CMe)–SCN–Cd(NCS)2(O2CMe)–NCS– and Cu(en)2 units. Each of two crystallographically independent cadmium atoms has six coordination, consisting of CdN4O2 or CdS2N2O2 distorted octahedral geometries. The copper atom of Cu(en)2 also exhibits a distorted octahedral arrangement. Apical bonds between the Cu(II) and S atoms from terminal NCS–groups [3.1113(12) and 3.1467(14)Å] link the anionic chains forming a 2D network. Variable-temperature magnetic susceptibility measurements of 1–3 show weak antiferromagnetic coupling between the copper centres. [Copyright &y& Elsevier]

A new organic-inorganic hybrid salt [L]2[MnCl4] (I) where L+ is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, is built of discrete organic cations and tetrachloridomanganate(II) anions. The L+ cation was formed in situ in the oxidative cyclocondensation of 2-pyridinecarbaldehyde and CH3NH2·HCl in methanol. The structure was refined as a two-component twin using PLATON (Spek, 2020[Spek, A. L. (2020). Acta Cryst. E76, 1-11.]) to de-twin the data. The twin law (-1 0 0 0 - 1 0 0.5 0 1) was applied in the refinement where the twin component fraction refined to 0.155-(1). The compound crystallizes in the space group P21/c with two crystallographically non-equivalent cations in the asymmetric unit, which possess similar structural conformations. The fused pyridinium and imidazolium rings of the cations are virtually coplanar [dihedral angles are 0.89-(18) and 0.78-(17)°]; the pendant pyridyl rings are twisted by 36.83-(14) and 36.14-(13)° with respect to the planes of the remaining atoms of the cations. The tetrahedral MnCl42- anion is slightly distorted with the Mn-Cl distances falling in the range 2.3469-(10)-2.3941-(9)-Å. The distortion value of 0.044 relative to the ideal tetrahedron was obtained by continuous shape measurement (CShM) analysis. In the crystal, the cations and anions form separate stacks propagating along the a-axis direction. The organic cations display weak π-π stacking. The anions, which are stacked identically one above the other, demonstrate loose packing; the minimum Mn...Mn separation in the cation stack is approximately 7.49-Å. The investigation of the fluorescent properties of a powdered sample of (I) showed no emission. X-band EPR data for (I) at 293 and 77-K revealed broad fine structure signals, indicating moderate zero-field splitting. [ABSTRACT FROM AUTHOR]