Synthesis, structure and solid state polymerization of diaquabis(propynoato)magnesium

Compounds of Antibacterial Agent Ciprofloxacin and Magnesium – Crystal Structures and Molecular Modeling Calculations

“…The total number of all the possible diastereoisomers could not be limited. Although the two Ow atoms lie at trans positions in most similar Mg II complexes, [39][40][41][42][43] their arrangement at cis positions has also been reported for a few similar Mg II complexes [44,45] and cannot be ruled out. After the Langevin dynamics simulated annealing calculations, we obtained the total energy results of 20 different conformations for each starting model (Table S4).…”

“…[37,38] However, the final structures of mer-[Mg(cfH) 3 ] 2+ exhibit lower energies by 0.4 kcal mol -1 in comparison to the energies of the fac isomers (Table S2). For the mer models we applied a set of harmonic restraints at the Mg II -O bonds [13,14,[39][40][41][42][43][44][45] during an additional minimization phase (Table S3). On the basis of these results we present the lowest energy model of one mer- [Mg(cfH) 3 ] 2+ enantiomer as the most favorable configuration of the complex (Scheme 4A).…”

“…Applying the distance restraints (Table S5) to Mg II -O bonds [13,14,[39][40][41][42][43][44][45] for the transOw model with the lowest energy and making corrections to the geometry by minimizing the energy of the complex once again, the structure of the predicted most stable isomer (a transOw isomer) has been obtained ( Figure 6). On the other hand, the trans3 isomers exhibit the highest average energy by more than 0.7 kcal mol -1 than the other isomers.…”

“…[56] For magnesium ions we used a default parameter set with R* = 2.20 Å and e* = 0.02 kcal mol -1 , since their van der Waals interactions are not expected to play a major role in such bonded representations as in octahedral complexes. Mg-O bond lengths were corrected in the final models using harmonic restraints with equilibrium values that were extracted from crystallographic data of similar compounds [13,14,[39][40][41][42][43][44][45] (Tables S3, S5 and Scheme S3). Nonbonded interactions were calculated in vacuo with no cutoff and the electrostatic energy term was treated using bond dipoles.…”

Preparation, Structure, and Solid-State Reactivity of Lanthanum Propynoates

“…Irradiation of solid metal propynoates with 60 Co γ-rays produces the corresponding metal polypropynoates . The factors that influence this unusual solid-state reactivity include the relative distance between the reactive acetylenic centers (including the required presence of infinite chains of short acetylene−acetylene contacts), crystal lattice energy, and the absorption cross section of the material for γ-rays. − Salts of the heavier metals show greater sensitivity to ionizing radiation, apparently a consequence of both lattice energy and absorption effects. ,,, Irradiation of solid “all-organic” acetylenes with apparent ideal alignment of reactive groups produces no significant product. − As part of a program to discover new radiation-sensitive heavy-metal carboxylates, we prepared a rare-earth propynoate of stoichiometry [La(O 2 CC⋮CH) 3 (OH 2 ) 3 ] 2 ( 1 ) and observed that a solid-state reaction occurred when 1 was exposed to 60 Co γ-rays. A possible strategy for the production of structurally related reactive solids containing the same metal involves the replacement of aqua ligands.…”