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Two new flexible dipyridyl building blocks, N,N‘-bis(4-picolinoyl)hydrazine (4-bph) and its N-orientation isomer N,N‘-bis(3-picolinoyl)hydrazine (3-bph), have been synthesized as versatile cocrystallizing agents and introduced into the reactions with pyromellitic acid (H4BTA) and fumaric acid (H2Fa). Hydrogen-bonded directed assemblies of two hydrates of bphs and four binary cocrystals were validated by single-crystal X-ray diffraction analysis. With the presence of the reliable hydrogen-bonding donor/acceptor(s) of bph, the crystalline lattices of 4-bph·2H2O (1) and 3-bph·2H2O (4) are managed by N−H···Owaterand O−H···Ocarbonylto afford one-dimensional (1D) arrays, which are further extended to distinct three-dimensional (3D) (for 1) and two-dimensional (2D) (for 4) networks via O−H···Npyridylinteractions. While for the concomitant polymorphs (H2BTA)·(H2-4-bph) (2and 3), charge-assistant bifurcated N−H···O bonds do favor 1D acid−base hydrogen-bonding tapes, which are interlinked to result in a 2D layer in 2and a 3D network in 3through the competition of O−H···Ocarboxyland O−H···Ocarbonylforces. (H3BTA)2·(H2-3-bph)·4H2O (5) is also a charge-transfer organic salt with a 2D bilayered array. Proton transfer from weak H2Fa to 3-bph is not observed, and this leads to the formation of a binary neutral cocrystal (H2Fa)·(3-bph) (6), in which the 2D undulating herringbone pattern is constructed via the expected carboxylpyridyl heterosynthon and amide−amide homosynthon. [ABSTRACT FROM AUTHOR]

The mol­ecular structure of the neutral mononuclear title complex, [Mn(NCS)2(C12H8N4O)2(H2O)2], is centrosymmetric; the MnII atom lies on an inversion center and is six-coordinate (MnN4O2), with an octa­hedral geometry comprising two trans monodentate 2,5-di-3-pyrid­yl-1,3,4-oxadiazole ligands, two thio­cyanate ligands and two bound water mol­ecules. Inter­molecular O—H⋯N hydrogen bonds between these monomeric units result in two-dimensional supramolecular layers with a parallel arrangement, which are stabilized by intra­layer aromatic stacking and further extended to a three-dimensional network via inter­layer weak C—H⋯S inter­actions. [ABSTRACT FROM AUTHOR]

In the title neutral mononuclear complex, [Cd(H2IDC)2(H2O)3]·H2O (H2IDC is the 4-carb­oxy-1 H-imidazole-5-carboxyl­ate anion, C5H3N2O4), the CdII atom is trans-coordinated by two H2IDC ligands and three aqua mol­ecules, displaying a distorted trigonal-bipyrimidal geometry. Inter­estingly, H2IDC coordinates in an N-monodentate fashion to the central CdII atom, which is unprecedented. A three-dimensional supramolecular network is generated through N—H⋯O and O—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

The mol­ecular structure of the neutral mononuclear complex [Fe(NCS)2(3-bpo)2(H2O)2], in which 3-bpo denotes 2,5-di-3-pyrid­yl-1,3,4-oxadiazole (C12H8N4O), is centrosymmetric, with FeII located on an inversion center. This complex is octa­hedral, and the FeII atom is trans coordinated by two monodentate NSC− ligands, two monodentate 3-bpo ligands and two water mol­ecules. Each complex is linked to four others, forming a (011) sheet, by O—H⋯N hydrogen bonding. Weak C—H⋯S inter­actions link each (011) sheet to the two adjacent sheets, hence forming a three-dimensional array. There is also some slipped π stacking within each sheet. [ABSTRACT FROM AUTHOR]

A new polymorph of 2,5-bis­(4-pyrid­yl)-1,3,4-thia­diazole, C12H8N4S, obtained under hydro­thermal conditions, is described. In this structure, the two terminal pyrid­yl groups are inclined to the central thia­diazole ring with dihedral angles of 6.47 (2) and 29.95 (5)°, and the dihedral angle between the pyrid­yl ring planes is 23.65 (6)°. An inter­molecular C—H⋯N weak inter­action is observed. The structural differences of two polymorphs of 2,5-bis­(4-pyrid­yl)-1,3,4-thia­diazole are also discussed. [ABSTRACT FROM AUTHOR]