The crystal structure of 3-((1R,2S)-1-methylpyrrolidin-1-ium-2-yl)pyridin-1-ium tetrachloridocobaltate(II) monohydrate, C₁₀H₁₈Cl₄CoN₂O

Hydrogen bonding versus packing effects in the crystal structure of 3-((1R,2S)-1-methylpyrrolidin-1-ium-2-yl)pyridin-1-ium tetraiodidozincate(II), C10H16I4ZnN2

“…The rotation around the C3-C2′ single bond causes a certain flexibility of the nicH 2 dication and the final orientation is more or less a consequence of the packing and the hydrogen-bonding scheme, respectively. The bond lengths and angles within the nicH 2 dication [7,11,12] as well as those in the [ZnI4] 2− ion [18][19][20] are in the expected ranges. The Zn-I bond lengths of the complex [ZnI4] 2− anion are: Zn1-I1 2.6298(4) Å, Zn1-I2 2.6117(4) Å, Zn1-I3 2.6109(4) Å and Zn1-I4 2.6176(4) Å.…”

“…The asymmetric unit of the title structure contains one 3-((1R,2S)-1-methylpyrrolidin-1-ium-2-yl)pyridin-1-ium (nicotin-1,1′-dium) dication (nicH 2 ) and one tetraiodidozincate(II) dianion. As discussed several times [7,11,12], the protonation at the nitrogen atom of the pyrrolinyl moiety creates a second chiral center at N1′ (cf. left part of the Figure), which shows R configuration in all reliable crystal structures deposited in the Cambridge Structural database so far.…”

“…As reported and summarized by one of us [7] structural data are available for (a) metal complexes, which contain neutral nicotine ligands; (b) a small number of co-crystals containing neutral nicotine as one of the components; (c) some examples for pyrrolidinylmonoprotonated nicotinium salts; and (d) mono-protonated nicotinium as a cationic ligand. As a result of the database survey specified above, only a limited number of examples of salt structures containing doubly protonated nicotinium cations have been reported so far [7][8][9][10][11][12]. This contribution is part of our continuing interest in synthesis, characterization and understanding of hydrogen-bonding schemes of salts of natural products [7,[11][12][13][14].…”

“…As a result of the database survey specified above, only a limited number of examples of salt structures containing doubly protonated nicotinium cations have been reported so far [7][8][9][10][11][12]. This contribution is part of our continuing interest in synthesis, characterization and understanding of hydrogen-bonding schemes of salts of natural products [7,[11][12][13][14]. The choice of a [ZnI4] 2− counter anion is part of our general interest in halogen bonding interactions between iodine containing molecules and ions, regardless of whether they are attractive or repulsive [15][16][17].…”