Solid-state and solution-state self-association of dimethylarsinic acid: IR, NMR and theoretical study

Self-association of diphenylpnictoginic acids in solution and solid state: covalent vs. hydrogen bonding

“…One can see that the structure of polymorph A is similar to 15 and to the chain polymorph of dimethylarsinic acid. 25 So, almost all structural parameters for 15, 14-A, 14-B and dimethylarsinic are similar (Table 1). The only exception is dihedral angle OXOÁ Á ÁO: this value is similar for 15 and 14-A (50-561), while for 14-B it is much larger (771).…”

“…The vicinal H/D isotope effects are δ (HD)– δ (HH) = −0.16 ppm and δ (HHD)– δ (HHH) = −0.21 ppm, δ (HDD)– δ (HHD) = −0.19 ppm, which indicate the cooperativity of hydrogen bonds. 25,38,39 Thus, diphenylarsinic acid 14 , similarly to dimethylarsinic acid, predominantly exists in solution in a form of cyclic dimers.…”

“…23 Five decades later, it was shown that dimethylarsinic acid in solid state forms zigzag chains 24 or dimers. 25 The recent investigation of cacodylic acid has demonstrated that in solution in a mixture of deuterated freon gases CDF 3 /CDF 2 Cl it forms cyclic dimers with strong hydrogen bonds, which are coupled cooperatively. 25 To date, cacodylic acid is the only organoarsinic acid studied both in a solution and in a solid state.…”

“…Selected geometrical parameters for 15, two polymorphs of 14 (data from this work) and dimethylarsinic acid (data given from ref 25)…”

Isotope Effects on Chemical Shifts in the Study of Hydrogen Bonds in Small Molecules

“…This has been extended to investigate heterodimers and heterotrimers of phosphinic and phosphoric acids (see Figure 12) [32]. Using the same technique, it could be proven that dimethylarsenic acid forms cyclic dimers in solution with two equivalent strong hydrogen bonds [33].…”