Non-covalent O···O interactions among isopolyanions using a cis-{MoO2} moiety by the assistance of N-H···O hydrogen bonds

Abstract

An inorganic-organic hybrid material, [2-AmpH] 4 [Mo 8 O 26 ](1) has been isolated by the reaction of Na 2 MoO 4 ·2H 2 O with 2-aminopyrimidine (2-Amp) from an acidic aqueous medium. In this low pH synthesis, the organic molecule (2-Amp) gets mono-protonated (2-AmpH + ) and acts as the cation in stabilizing the octamolybdate anion in 1. Compound 1 crystallizes in the triclinic space group P-1 with a = 9⋅925 (3) (4), β = 64⋅907(4), γ = 89⋅506(4)°, Z = 1. An interesting three-dimensional supramolecular structure, having well-defined channels, is formed through N-H⋅⋅⋅O and C-H⋅⋅⋅O hydrogen bonds, in which the protonated organic cation plays a significant role. The crystal structure also reveals an unusual cluster-cluster (non-covalent O⋅⋅⋅O) interaction using cis-(MoO 2 } moieties of the isopolyanion. N-H⋅⋅⋅O hydrogen bonds, originated from pyridimidinium cation and isopolyanion, are found to influence to attain such non-covalent O⋅⋅⋅O interactions among polyoxometalate anions. An interesting helical arrangement, formed from isopolyanion and organic cation, is observed.

Novel Countercation in MMX-Type Mixed-Valence Chain Compound: Coexistence of Neutral and Protonated Amino Substituents

“…This partial deprotonation of diammonium ion has not been observed in any MMX chains synthesized so far. Although several kinds of compounds containing mono-protonated diamines as countercation have been reported [32][33][34][35][36], these compounds were synthesized from neutral diamines with acid. It should be noted that 1 differs from them in that it was synthesized from fully protonated diammonium, {o-(H 3 NC 6 H 4 NH 3 )}SO 4 , via the deprotonation.…”

Nature and Strength of Weak O⋅⋅⋅O Interactions in Nitryl Halide Dimers

“…With regards to the intermolecular O•••O interactions, they were mainly identified within electron densities of crystal structures. For instance, Bianchi et al [8] found an intermolecular O•••O contact (OÀ O distance shorter than the sum of the van der Waals radii) between Mn 2 (CO) 10 complexes in metallo-carbonyl crystals through an accurate X-ray diffraction analysis at 120 K. Besides, Arumuganathan et al [9] also reported a close O•••O contact between polyoxometalate moieties of cis-{MoO 2 } complexes. In another QTAIM study on the crystal structure of dinitrogen tetroxide, Tsirelson et al [10] have found that the multiple O•••O interactions between N 2 O 4 molecules can also be characterized as "hole-lump" interactions.…”

“…For instance, Bianchi et al [8] . found an intermolecular O⋅⋅⋅O contact (O−O distance shorter than the sum of the van der Waals radii) between Mn 2 (CO) 10 complexes in metallo‐carbonyl crystals through an accurate X‐ray diffraction analysis at 120 K. Besides, Arumuganathan et al [9] . also reported a close O⋅⋅⋅O contact between polyoxometalate moieties of cis‐{MoO 2 } complexes.…”