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The isostructural coordination polymers, M(isonicotinate)(tyrosinate)(H2O)2 [M = Co or Ni] have been synthesized by microwave-assisted hydrothermal methods. These compounds crystallize in the non-centric space group P21. At 290 K, for the cobalt analogue the unit cell parameters are a = 6.0658(6), b = 15.540(2), c = 9.1328(9) A, β = 107.052(7)°, V = 823.05(16) A3; for the nickel compound a = 6.0946(8), b = 15.443(2), c = 9.1202(11) A, β = 107.803(10)°, V = 817.28(19) A3. The structure contains linear chains with composition [M(isonicotinate)]∞ in which the isonicotinate is arranged head-to-tail and binds to octahedral cations through both pyridine and monodentate carboxylate functions. At each metal centre the coordination is completed by two cis water molecules and tyrosinate that chelates to the metal centre through monodentate carboxylate and amine groups. The chains run parallel to the crystallographic [101] direction. Between the chains there is extensive hydrogen bonding between bound water and carboxylate groups. The cobalt compound loses water upon heating above room temperature and continues to lose mass in ill-defined steps upon further heating; in contrast the nickel compound loses mass in well-defined steps. An achiral one dimensional chain can be decorated with the chiral auxiliary tyrosine to produce a homochiral coordination polymer.

Single crystal of a new polymorph of 1,3,5-triazine-2,4,6-triaminehexaacetic acid has been growth and characterized. The structure of the title polymorph crystallized in the monoclinic space group C2/c with the unit cell parameters a = 20.443(4) A, b = 10.5104(14) A, c = 9.8022(11) A, β = 118.212(6)°, V = 1855.9(5) A3, Z = 4, R = 0.112, Rw = 0.273 and S = 1.038. The principal feature of the new polymorph is characterized by a bundle of molecular columns each of which is built up of molecular units stacked along c in the offset face-to-face manner. Significance of hydrogen bonding interactions in regulating the assembly of molecules in the structure is then demonstrated. Detailed differences in molecular conformation, type and pattern of hydrogen bonding interactions are discussed and distinguished from the previous polymorph. The vibrational and electronic spectroscopic studies are included. Microwave-assisted crystal growth and structure of 1,3,5-triazine-2,4,6-triaminehexaacetic acid new polymorph.

The first example of polyoxovanadate layered framework with a cobalt coordination complex as a pillaring unit, CoII(μ-C2N2H8)2[V 4 IV V 2 V O14], was readily synthesized under hydrothermal conditions. The structure can be solved and refined in monoclinic P2 1 /n with a = 9.143(3) A, b = 6.5034(11) A, c = 15.874(4) A, β = 101.90(2), V = 923.6(4) A3 and Z = 2. The crystal structure comprises two-dimensional {V 4 IV V 2 V O14}2− layers extending parallel to [101], constructed from tetrahedral {VVO4} and square pyramidal {VIVO5} building units. Adjacent layers are linked through the octahedral {CoIIO2(μ-C2N2H8)2} pillars, within which the CoII resides on an inversion center. The structure displays N–H···O and C–H···O hydrogen bonding between the ethylenediamine and vanadium oxide layers. A new polyoxovanadate layered framework pillared with a cobalt coordination complex, CoII(μ-C2N2H8)2[V 4 IV V 2 V O14], has been prepared hydrothermally and fully characterized.