3141-12-6Relevant academic research and scientific papers
Pnictogen bonding with alkoxide cages: Which pnictogen is best?
Trubenstein, Henry J.,Moaven, Shiva,Vega, Maythe,Unruh, Daniel K.,Cozzolino, Anthony F.
supporting information, p. 14305 - 14312 (2019/09/30)
Pnictogen bonding is beginning to emerge as a useful supramolecular interaction. The design strategies for these systems are still in the early stages of development and much attention has been focused on the lighter pnictogens. Pnictogen bond donors can have up to three independent sites for binding which can result in triple pnictogen bonding. This has been observed in the self-Assembly of antimony alkoxide cages, but not with the lighter congeners. This work reports structural characterization of an analogous arsenic alkoxide cage that engages in a single pnictogen bond and synthetic explorations of the bismuth congener. DFT calculations are used to evaluate the differences between the structures. Ultimately the partial charge on the pnictogen and the energy of the pnictogen lone pair dictate the strength, orientation and number of pnictogen bonds that these cages form. Antimony cages strike the best balance between strength and directionality, allowing them to achieve triple pnictogen bonding where the other congeners do not.
Determination of the mean enthalpy of dissociation of arsenic-oxygen bonds in some arsenic (III) alkoxides
De Souza, Antonio G.,Brasilino, Maria G.A.,Airoldi, Claudio
, p. 1359 - 1367 (2007/10/03)
The standard molar enthalpy of formation of arsenic alkoxides in the liquid phase, As(OR)3 {R = ethyl (Et), n-propyl (Prn), i-propyl (Pri), n-butyl (Bun), and i-butyl (Bui)}, was determined through reaction-solution calorimetry in chloroform based on the reaction: As(NEt2)3(1) + 3ROH(1) = As(OR)3(1); ΔsolHmo at T = 298.15 K. This series of alkoxides gave the following molar enthalpy of formation ΔfHmo values: -(758.1 ± 9.0) kJ · mol-1, -(774.3 ± 9.0) kJ · mol-1, -(809.8 ± 9.0) kJ · mol-1, -(828.8 ± 8.9) kJ · mol-1, and -(863.4 ± 8.9) KJ · mol-1, respectively. The standard molar enthalpies of vaporization ΔvapHm (47.9 ± 1.1) kJ · mol-1, (51.2 ± 1.8) kJ · mol-1, (80.1 + 0.9) kJ · mol-1, (64.0 ± 1.8) kJ · mol-1 and (75.7 ± 1.2) kJ · mol-1, were obtained for the same sequence of alkoxides, by means of differential scanning calorimetry. By combining the preceding values with the standard molar enthalpy of formation of the alkoxide ΔfHm in the liquid phase, the standard molar enthalpy of formation of these compounds in the gas phase was obtained as -(710.2 ± 9.0) kJ · mol-1, -(723.1 ± 9.1) kJ · mol-1, -(729.3 ± 9.0) kJ · mol-1, -(764.8 ± 9.1) kJ · mol-1, and -(787.7 ± 9.0) kJ · mol-1, respectively. From these values, the mean enthalpy of dissociation of the arsenic-oxygen bond 〈Dm〉(As-O) was calculated for the sequence of the above alkoxides to give: (320 ± 5) kJ · mol-1, (301 ± 5) kJ · mol-1, (292 ± S) kJ · mol-1, (293 ± 5) kJ · mol-1, and (294 ± 5) kJ · mol-1. The linear correlation between the standard molar enthalpies of formation of the liquid alkoxides ΔfHm{As(OR)3,1} and the respective alcohol ΔfHm(ROH,1), suggests that these thermochemical data can be assessed for a series of normal and iso chain alcohols.
