Synthesis, crystal structure and third-order non-linear optical properties of two-dimensional supramolecular polymer [Co2(μ2-4,4′- bipy)2(μ2-be)2(be)2]n

Crystal structure of a novel one-dimensional zigzag chain-like cobalt(II) coordination polymer constructed from 4,4'-bi-pyridine and 2-hy-droxy-benzoate ligands

The synthesis, crystal structure and physical properties of a novel one-dimensional zigzag chain-like Co^II coordination polymer, [Co₂(2-OHbenz)₄(4,4′-bpy)_2.5(H₂O)]_n, constructed from 4,4′-bi­pyridine (4,4′-bpy) and 2-hy­droxy­benzoate (2-OHbenz) are reported.

A novel one-dimensional zigzag chain-like Co^II coordination polymer constructed from 4,4′-bi­pyridine (4,4′-bpy) and 2-hy­droxy­benzoate (2-OHbenz) ligands, namely, catena-poly[[(4,4′-bi­pyridine-κN)­(μ-2-hy­droxy­benzoato-κ²O:O′)(2-hy­droxy­benzoato-κ²O,O′)cobalt(II)]-μ-4,4′-bi­pyridine-κ²N:N′-[aquahemi(μ-4,4′-bi­pyridine-κ²N:N′)(2-hy­droxy­benzoato-κO(2-hy­droxy­benzoato-κ²O:O′)cobalt(II)], [Co₂(C₇H₅O₃)₄(C₁₀H₈N₂)_2.5(H₂O)]_n, has been synthesized by reacting cobalt(II) nitrate trihydrate, 4,4′-bpy and 2-hy­droxy­benzoic acid in a mixture of water and methanol at room temperature. There are two independent Co^II centers, Co1 and Co2, in the asymmetric unit, revealing a distorted octa­hedral geometry with chromophore types of [CoN₂O₄] and [CoN₂O₃O′], respectively. The Co1 ions are doubly bridged by 2-OHbenz ligands with syn–anti coordination mode, generating a dinuclear unit. The bridging 4,4′-bpy ligands connect these dinuclear units and the mononuclear Co2 chromophores, providing a one-dimensional alternating zigzag chain-like structure. In the crystal, inter­molecular hydrogen bonds, C—H⋯π and π–π stacking inter­actions are observed and these help to consolidate the packing. In addition, the physical properties of the title compound are reported.

Nonlinear optical properties, upconversion and lasing in metal–organic frameworks

The building block modular approach that lies behind coordination polymers (CPs) and metal–organic frameworks (MOFs) results not only in a plethora of materials that can be obtained but also in a vast array of nonlinear optical properties that could be aimed at.

Crystal structure of bis-(μ-4-nitro-benzoato-κ2O:O')bis-[bis-(4-methyl-pyridine-κN)(4-nitro-benzoato-κ2O,O')manganese(II)]

The title compound, [Mn2(C7H4NO4)4(C6H7N)4] or [Mn2(μ-NBz)2(κ2-NBz)2(4-Mepy)4], where NBz is 4-nitro-benzoate and 4-Mepy is 4-methyl-pyridine, is a centrosymmetric dinuclear complex in which the MnII atoms are bridged by two NBz ligands with Mn⋯Mn = 4.1324 (4) Å. The MnII atom in this dimeric species is present in a distorted octa-hedral environment with the four coordinating O atoms forming the equatorial plane and the two pyridyl N atoms occupying the axial sites. An important structural feature of the dimeric complex is that each of the bridging carboxyl-ate ligands binds to the metal ions in an asymmetric fashion involving bent and linear Mn-O-C units. The crystal packing is consolidated by C-H⋯O and C-H⋯π interactions.

Bis(μ2-benzoato-κ(2) O:O')bis-[(benzoato-κ(2) O,O')bis(4,4'-bi-pyridine-κN)cobalt(II)]-benzoic acid (1/6)

In the title compound, [Co₂(C₇H₅O₂)₄(C₁₀H₈N₂)₄]·6C₆H₅COOH, the centrosymmetric cobalt dimer co-crystallizes with six mol­ecules of benzoic acid. Each Co^II atom is coordinated by four O atoms in a distorted square-planar arrangement while the N atoms are located in apical positions. The dihedral angles between the rings comprising each of the 4,4′-bipyridyl ligands are 25.2 (2) and 22.8 (2)°. In the crystal, the three-dimensional network is assembled by O—H⋯O and C—H⋯O hydrogen bonds.