Dimethyl-ammonium 3-carb-oxy-benzoate

In situ deca-rbonylation of N,N-di-methyl-formamide to form di-methyl-ammonium cations in the hybrid framework compound {[(CH3)2NH2]2[Zn{O3PC6H2(OH)2PO3}]} n

The title phospho-nate-based organic-inorganic hybrid framework, poly[bis(dimethylammonium) [(μ4-2,5-dihydroxybenzene-1,4-diphosphonato)zinc(II)]], {(C2H8N)2[Zn(C6H4O8P2)]} n , was formed unexpectedly when di-methyl-ammonium cations were formed from the in situ deca-rbonylation of the N,N-di-methyl-formamide solvent. The framework is built up from ZnO4 tetra-hedra and bridging di-phospho-nate tetra-anions to generate a three-dimensional network comprising [100] channels occupied by the (CH3)2NH2 + cations. Within the channels, an array of N-H⋯O hydrogen bonds help to establish the structure. In addition, intra-molecular O-H⋯O hydrogen bonds between the appended -OH groups of the phenyl ring and adjacent PO3 2- groups are observed.

Di-methyl-ammonium 2,4,5-tri-carb-oxy-benzoate: an example of the deca-rbonylation of N,N-di-methyl-formamide in the presence of a metal and a benzene-polycarb-oxy-lic acid. Is zirconium(IV) the Tsotsi?

The title salt, C2H8N+·C10H5O8-, was the unexpected product of an attempt to prepare a ZrIV metal-organic framework with benzene-1,2,4,5-tetra-carb-oxy-lic acid (1,2,4,5-H3B4C). In the reaction, the DMF solvent has been decarb-on-yl-ated, forming the di-methyl-ammonium cation, with one proton lost from the tetra-carb-oxy-lic acid. It is proposed that the ZrIV salt acts as a Tsotsi or robber, plundering CO from the DMF mol-ecule. The resulting salt crystallizes with two cations and two anions in the asymmetric unit. An intra-molecular hydrogen bond forms between a carb-oxy-lic acid substituent and the carboxyl-ate group of each of the monodeprotonated (1,2,4,5-H3B4C-) anions. In the crystal, an extensive array of O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds generates a three-dimensional network, with columns of cations and anions forming along the b axis.

Adenin-1-ium hydrogen isophthalate di-methyl-formamide monosolvate

In the title proton-transfer organic salt, C5H6.3N5 (+)·C8H4.7O4 (-)·C3H7NO, the adeninium moiety is protonated at the N atom in the 1-position of the 6-amino-7H-purin-1-ium (adeninium) cation. In the solid state, the second acidic proton of isophthalic acid is partially transferred to the imidazole N atom of the adeninium cation [refined O-H versus N-H ratio = 0.70 (11):0.30 (11)]. Through the partially transferred proton, the adeninium cation is strongly hydrogen bonded (N-H⋯O/O-H⋯N) to the isophthalate anion. This strong inter-action is assisted by another N-H⋯O hydrogen bond originating from the adeninium NH2 group towards the isophthalate keto O atom, with an R (2) 2(8) graph-set motif. This arrangement is linked via N-H⋯O hydrogen bonds to the O atoms of the carboxyl-ate group of an isophthalate anion. Together, these hydrogen bonds lead to the formation criss-cross zigzag isophthalate⋯adeninium chains lying parallel to (501) and (50-1). The adeninium cations and the isophthalate anions are arranged in infinite π stacks that extend along the c-axis direction [inter-planar distance = 3.305 (3) Å]. Mol-ecules are inclined with respect to this direction and within the stacks they are offset by ca. half a mol-ecule each. Combination of the N-H⋯O and O-H⋯N hydrogen bonds with the π-π inter-actions forms infinitely stacked isophthalate⋯adeninium chains, thus leading to a two-dimensional supra-molecular structure with parallel inter-digitating layers formed by the π stacked isophthalate⋯adeninium chains. The DMF mol-ecules of crystallization are bonded to the adeninium cations through strong N-H⋯O hydrogen bonds and project into the lattice space in between the anions and cations. There are also C-H⋯O hydrogen bonds present which, combined with the other inter-actions, form a three-dimensional network. The crystal under investigation was found to be split and was handled as if non-merohedrally twinned.