Noncovalent Interactions in 2-Mercapto-1-methylimidazole Complexes with Organic Iodides

Abstract

2-Mercapto-1-methylimidazole (mmim) forms complexes with organic iodides, 1,4-diiodotetrafluorobenzene (p-F4DIB), tetraiodoethylene (TIE), and 1,2-diiodotetrafluorobenzene (o-F4DIB), in which there are remarkably similar N−H···S hydrogen bonding and S···I halogen bonding patterns. Extended chains of alternating donor (mmim) and acceptor (p-F4DIB and TIE) molecules are formed through divalent I···S···I interactions. These chains are joined into double strands through N−H···S interactions that link two mmim molecules into a dimer. In the third complex, N−H···S bound dimers are linked into infinite chains through S···I interactions involving a pair of o-F4DIB molecules. Thermal analysis indicates that decomposition in both of the F4DIB complexes proceeds through total loss of acceptor, while decomposition of the TIE complex involves a combination of acceptor loss and acceptor reaction. Melting in the o-F4DIB complexes appears to be preceded by a solid-state rearrangement or premelting phenomenon that is not observed in the other two complexes. Crystal data for mmim· p-F4DIB: monoclinic space group, C2/c (no. 15), a = 26.915(3) Å, b = 7.9216(6) Å, c = 14.2630(4) Å, β = 105.618(1)°, V = 2928.7(4) Å3, Z = 8, ρcalc = 2.34 g/cm3. Crystal data for mmim·TIE: monoclinic space group, C2/c (no. 15), a = 20.1789(12) Å, b = 10.7824(10) Å, c = 14.5072(2) Å, β = 118.767(1)°, V = 2766.9(3) Å3, Z = 8, ρcalc = 3.10 g/cm3. Crystal data for mmim· o-F4DIB: triclinic space group, P1̄ (no. 2), a = 7.4987(7) Å, b = 8.1906(12) Å, c = 11.6512(12) Å, α = 83.245(4)°, β = 84.695(3)°, γ = 86.135(3)°, V = 706.35(14) Å3, Z = 2, ρcalc = 2.43 g/cm3.

Halogen Bonding in Crystal Engineering

“…The halogen and hydrogen bonds in the structure of (mmim)·(1,2-TFIB). [38] As mentioned previously, oxygen can also be used as an XB acceptor to construct supramolecular structures. Co-crystals of the nitroxide 1,1,3,3-tetramethylisoindolin-2-yloxyl (TMIO) and 1,2-TFIB are formed under standard sublimation conditions.…”

“…[22,34,35] In the present study, however, we focus first on the XB systems with the less commonly used isomer of diiodotetrafluorobenzene, i.e., 1,2-diiodoterfluorobenzene (1,2-TFIB). [33,34,[36][37][38][39] We will use 1,2-TFIB as the "probe donor" to study the halogen bonding interactions with different type of XB acceptors and to elucidate how the halogen bonding acceptor affects the properties of halogen bonding.…”

“…9). [38] The mmim molecule and 1,2-TFIB form a complex, in which N-H … S bound imidazole dimers are connected through C-I … S interactions to a pair of 1,2-TFIB molecules, forming infinite chains. The C-I … S bonds are different in strength (the C-I … S distance of the weaker one was 3.843 Å, while the stronger one was 3.291 Å) and the bonds involving sulphur can be defined as trifurcated bonds.…”

Reactivity of Polyiodides Towards 1,3‐Bis(4‐pyridyl)propane (bpp): A New CuI Cluster Polycatenane Framework and a Novel 2D AgI Cluster Motif

“…[9a] In 4, all these interactions are considerably shorter than the sums of the van der Waals contact distances for the atoms involved (N: 1.55-1.61 Å; I: 1.98-2.00 Å). [19] The anti-anti configuration of bpp is also retained. …”

Pentaerythritol tetrakis(4-iodo-2,3,5,6-tetrafluorophenyl) ether: a tecton for the self-assembly of double strand 1D infinite chains

“…Halogen bonding has been used to drive effectively the formation of a wide diversity of supramolecular architectures. Nitrogen [3], oxygen [4], and sulfur [5] atoms or halide anions [6] have been the more commonly employed electron donor motifs. Halogen molecules (mainly iodine and bromine, but also chlorine and interhalogens or pseudohalogens) [7] have been the electron acceptors more frequently used in the sixties, while recently iodobenzene [4d-g] and iodoacetylene derivatives [6e -i] have received particular attention.…”