Synthesis, Crystal Structures, and Magnetic Properties of Cyano-Bridged Honeycomblike Layers MV−CuII (M = Mo, W) Chelated by a Macrocyclic Ligand

Crystal structure of di-aqua-(3,14-diethyl-2,6,13,17-tetra-aza-tri-cyclo-[16.4.0.07,12]docosa-ne)copper(II) (3,14-diethyl-2,6,13,17-tetra-aza-tri-cyclo[16.4.0.07,12]docosa-ne)copper(II) tetra-bromide dihydrate, [Cu(C22H44N4)(H2O)2][Cu(C22H44N4)]Br4·2H2O

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-tetra-aza-tri-cyclo-[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 mol-ecule. The CuII atom in the first complex exists in a tetra-gonally distorted octa-hedral 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 nitro-gen 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 inter-molecular hydrogen bonds involving the macrocycle N-H or C-H groups and the O-H groups of water mol-ecules as donor groups, and the O atoms of water mol-ecules and bromide anions as acceptor groups, giving rise to a one-dimensional network extending parallel to [100].

Crystal structure of di-aqua-(3,14-diethyl-2,6,13,17-tetra-aza-tri-cyclo-[16.4.0.07,12]docosa-ne)copper(II) dichloride tetra-hydrate

The crystal structure of the novel hydrated CuII salt, [Cu(L)(H2O)2]Cl2·4H2O (L = 3,14-diethyl-2,6,13,17-tetra-aza-tri-cyclo-[16.4.0.07,12]docosane, C22H44N4) has been determined using synchrotron radiation. The asymmetric unit contains one half of the [Cu(L)(H2O)2]2+ cation (completed by crystallographic inversion symmetry), one chloride anion and two lattice water mol-ecules. The copper(II) atom exists in a tetra-gonally distorted octa-hedral environment with the four N atoms of the macrocyclic ligand in equatorial and two O atoms from water mol-ecules in axial positions. The latter exhibit a long axial Cu-O bond length of 2.7866 (16) Å due to the Jahn-Teller distortion. The macrocyclic ring adopts a stable trans-III conformation with typical Cu-N bond lengths of 2.0240 (11) and 2.0441 (3) Å. The complex is stabilized by hydrogen bonds formed between the O atoms of coordinated water mol-ecules and the NH groups as donors, and chloride anions as acceptors. The chloride anions are further connected to the lattice water solvent molecules through O-H⋯Cl hydrogen bonds, giving rise to a three-dimensional network structure.

Crystal structure of 3,14-diethyl-2,6,13,17-tetra-azoniatri-cyclo-[16.4.0.07,12]docosane tetra-chloride tetra-hydrate from synchrotron X-ray data

The crystal structure of the hydrated title salt, C22H48N4 4+·4Cl-·4H2O (C22H48N4 = H4 L = 3,14-diethyl-2,6,13,17-tetra-azoniatri-cyclo-[16.4.0.07,12]doco-sa-ne), has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit comprises one half of the macrocyclic cation (completed by crystallographic inversion symmetry), two chloride anions and two water mol-ecules. The macrocyclic ring of the tetra-cation adopts an exodentate (3,4,3,4)-D conformation. The crystal structure is stabilized by inter-molecular hydrogen bonds involving the macrocycle N-H groups and water O-H groups as donors, and the O atoms of the water mol-ecules and chloride anions as acceptors, giving rise to a three-dimensional network.

Synthesis, Crystal Structure, Spectroscopic Properties, and Hirshfeld Surface Analysis of Diaqua [3,14-dimethyl-2,6,13,17 tetraazatricyclo(16.4.0.07,12)docosane]copper(II) Dibromide

A newly prepared Cu(II) complex salt, Cu(L1)(H2O)2Br2, where L1 is 3,14-dimethyl-2,6,13,17-tetraazatricyclo(16.4.0.07,12) docosane, is characterized by elemental and crystallographic analyses. The Cu(II) center is coordinated by four nitrogen atoms of macrocyclic ligand and the axial position by two water molecules. The macrocyclic ligand adopts an optimally stable trans-III conformation with normal Cu–N bond lengths of 2.018 (3) and 2.049 (3) Å and long axial Cu1–O1W length of 2.632 (3) Å due to the Jahn–Teller effect. The complex is stabilized by hydrogen bonds formed between the O atoms of water molecules and bromide anions. The bromide anion is connected to the neighboring complex cations and water molecules through N–H···Br and O–H···Br hydrogen bonds, respectively. The g-factors obtained from the electron spin resonance spectrum show the typical trend of g∥ > g⊥ > 2.0023, which is in a good accordance to the dx2-y2 ground state. It reveals a coordination sphere of tetragonal symmetry for the Cu(II) ion. The infrared and electronic absorption spectral properties of the complex are also discussed. Hirshfeld surface analysis represents that the H···H, H···Br/Br···H and H···O/O···H contacts are the major molecular interactions in the prepared complex.

Crystal structure of 3,14-diethyl-2,13-di-aza-6,17-diazo-niatri-cyclo-[16.4.0.07,12]docosane dinitrate dihydrate from synchrotron X-ray data

The crystal structure of title salt, C22H46N4 2+·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 mol-ecule. The mol-ecular dication, C22H46N4 2+, together with the nitrate anion and hydrate water mol-ecule are involved in an extensive range of hydrogen bonds. The mol-ecule is stabilized, as is the conformation of the dication, by forming inter-molecular N-H⋯O, O-H⋯O, together with intra-molecular N-H⋯N hydrogen bonds.

Auxiliary ligand-induced structural diversities of octacyanometalate-based heterobimetallic coordination polymers towards diverse magnetic properties

Three octacyanometalate-based bimetallic coordination polymers (CPs), {[μ₄-M^V(CN)₈][Co(DMF)₄]₂(ClO₄)}_n (M = W CP-1, Mo CP-2) and {[μ₄-W^IV(CN)₈]Co₂(azpy)₄}_n CP-3, were synthesized in the absence (for CPs 1 and 2) or presence (for CP-3) of auxiliary ligand 4,4'-azopyridine (azpy), respectively. CPs 1 and 2 exhibit the same three-dimensional (3D) polymeric cation frameworks with [ClO₄]^- as the counterions, while CP-3 displays a porous 3D framework in an unusual 2-nodal (4,6)-connected 4,6T155 topology with point symbol as {4²·6⁴}{4⁶·6⁴·7·8⁴}₂. Notably is that octacyanometalate [W^V(CN)₈]^3- has been reduced into [W^IV(CN)₈]^4- during the synthetic process of CP-3. The magnetic investigations indicate that CP-1 exhibits the typical ferromagnetic property due to the ferromagnetic coupling between W(v) and Co(ii) spin centers, while CP-3 displays the weak ferromagnetic interaction at low temperature, which is consistent with the valence change of W center in CP-3.

Tuning of chain chirality by interchain stacking forces and the structure-property relationship in coordination systems constructed by meridional FeIII cyanide and MnIII Schiff bases

We synthesized six Fe(iii)-Mn(iii) bimetallic compounds by self-assembling the newly developed mer-Fe cyanide PPh₄[Fe(Clqpa)(CN)₃]·H₂O (1) and PPh₄[Fe(Brqpa)(CN)₃]·H₂O (2) with Mn Schiff base Mn(5-Xsalen)⁺ cations. These compounds include [Fe(Xqpa)(CN)₃][Mn(5-Ysalen)]·pMeOH·qH₂O [qpaH₂ = N-(quinolin-8-yl)picolinamide; salen = N,N'-ethylenebis(salicylideneiminato) dianion; X = Cl, Y = H (3); X = Cl, Y = Br (4); X = Br, Y = H (5); X = Br, Y = F (6); X = Br, Y = Cl (7); X = Br, Y = Br (8)]. When precursor 1 was used, compounds 3 and 4 were isolated to give a dinuclear entity and a linear chain structure, respectively. The reaction of precursor 2 with the Schiff bases afforded four linear Fe(iii)-Mn(iii) chain complexes. Chain chirality with P- and M-helicity emerges in 4, 7, and 8, while 5 exhibits chain helicity opposite to the previous chain complexes and 6 presents no chain helicity. Such a structural feature is heavily dependent on the interchain π-π contacts and the Fe precursor bridging unit. Chiral induction from a local ethylenediamine link of Y-salen is propagated over the chain via noncovalent π-π interactions. All the bimetallic compounds show antiferromagnetic interactions transmitted by the cyanide linkage. A field-induced metamagnetic transition is involved in 4, 7, and 8, while a field-induced two-step transition is evident in 6. From a magnetostructural viewpoint, the coupling constant is primarily governed by the Mn-N_ax-C_ax angle (ax = axial) in the bimetallic chain complexes composed of mer-Fe(iii) tricyanides, although the torsion angle plays a role.

A new family of [CuIILnIIIMV] heterotrimetallic complexes (Ln = La, Gd, Tb; M = Mo, W): model systems to probe exchange interactions and single-molecule magnet properties

Four 3d–4f–4(5)d heterotrimetallic complexes, [L²CuLn(H₂O)₅(μ-NC)M(CN)₇], were obtained from the association of the binuclear 3d–4f complexes and {M^V(CN)₈}³⁻ metalloligands.

Covalent embedding of Ni2+/Fe3+ cyanometallate structures in silica by sol-gel processing

Compound [Ni(AEAPTS)2]3[Fe(CN)6]2 (AEAPTS = N-(2-aminoethyl)-3-aminopropyltrimethoxysilane), in which Ni(2+) and Fe(3+) ions are ferromagnetically coupled through cyano bridges, was prepared. Sol-gel processing of the AEAPTS derivative resulted in incorporation of the cyanometallate in silica. The obtained material is magnetically ordered below 22 K with an effective magnetic moment μeff of 4.46 μB at room temperature, a maximum of 8.60 μB at approximately 15 K and a narrow hysteresis at 2 K, with a saturation remanence of about 300 emu mol(-1) and a coercitivity of 0.03 T.

X-ray structure and spectroscopy of novel trans-[Ni(L)(NO(3))(2)] and [Ni(L)](ClO(4))(2)·2H(2)O complexes

Ni(L)(NO(3))(2) (complex 1) and [Ni(L)](ClO(4))(2)·2H(2)O (complex 2) [L=3,14-diethyl-2,6,13,17-tetraazatricyclo(16.4.0.0(7,12))docosane] have been prepared and structurally characterized by single-crystal X-ray diffraction at 200K. For these constrained macrocycle complexes, nickel(II) exists in a distorted octahedral environment with the four nitrogen atoms of the macrocyclic ligands and two oxygen atoms from nitrate in axial positions in complex 1. The macrocyclic ligand in complex 1 adopts the most stable trans-III conformation. The Ni-N distances in both the complex 1 (2.094(4)-2.051(4)Å) and complex 2 (2.042(8)-1.996(7)Å), are typical but the axial ligands are coordinating, with NiO bond length, 2.198(3)Å for complex 1. The complex 2 adopts square planner geometry around the Ni(II) with four nitrogen atoms from macrocyclic ligand. The crystals are stabilized in a 3-D network by intra and intermolecular hydrogen bonds that are formed among the secondary nitrogen hydrogen atoms and nitrate in 1, and intermolecular hydrogen bonds are formed by perchlorate and NH groups in 2. The electronic absorption, IR and PL spectral properties are also discussed.

3,14-Diethyl-2,13-di-aza-6,17-diazonia-tri-cyclo-[16.4.0.0(7,12)]docosane dichloride tetra-hydrate from synchrotron radiation

The asymmetric unit of title hydrated salt, C₂₂H₄₆N₄²⁺·2Cl⁻·4H₂O, comprises half a centrosymmetric dication, one Cl⁻ anion and two water mol­ecules of crystallization. The structure determination reveals that protonation has occurred at diagonally opposite amine N atoms, and that the dication features intra­molecular N—H⋯N hydrogen bonds. In the crystal, a three-dimensional artchitecture is formed by O—H⋯Cl/N and N—H⋯Cl/O hydrogen bonds.

2,13-Dibenzyl-5,16-diethyl-2,6,13,17-tetra-aza-tricyclo-[16.4.0.0]docosan-2-ium nitrate

One of the tertiary amine atoms has been protonated in the title salt, C₃₆H₅₇N₄⁺·NO₃⁻. The four N atoms of the macrocycle are almost coplanar (r.m.s. deviation = 0.0053 Å), a result correlated with the formation of intra­molecular N—H⋯N and N—H⋯(N,N) hydrogen bonds. With respect to this plane, the benzyl groups lie to either side; a similar arrangement pertains for the cyclo­hexyl rings (each with a chair conformation). Helical supra­molecular chains are evident in the crystal, whereby alternating cations and anions are linked by C—H⋯O inter­actions. The chains are consolidated into supra­molecular arrays in the ab plane via C—H⋯π contacts involving both benzene rings.

Tris[tris-(ethane-1,2-diamine)cobalt(II)] bis-[octa-cyanidomolybdate(V)] dihydrate

In the title compound, [Co^II(C₂H₈N₂)₃]₃[Mo^V(CN)₈]₂·2H₂O, N—H⋯N and N—H⋯O hydrogen-bonding inter­actions give rise to a three-dimensional network. In the crystal structure, each Mo polyhedron has a square-anti­prismatic shape, while the Co complexes show distorted octa­hedral geometry with an occupancy of 50%. One of the Co atoms resides on a crystallographic inversion centre.