Synthons Competition/Prediction in Cocrystallization of Flexible Dicarboxylic Acids with Bent Dipyridines

Abstract

On the basis of the primary carboxyl/pyridyl hydrogen-bonded synthon, 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) and its 4-N-donor isomer 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) were assembled with flexible dicarboxylic acids possessing variable chain lengths to afford a series of organic cocrystalline materials. [Fumaric acid]‚[3-bpo] (1) has a two-dimensional (2-D) layered supramolecular pattern. [Fumaric acid]‚[4-bpo] (2) has linear tapes connected via carboxyl/pyridyl heterosynthons and further creates a three-dimensional (3-D) square net with the CdSO 4 topology combining with other weak interactions. [Suberic acid]‚[3-bpo] (3), obtained in ambient conditions, exhibits a 3-D corrugated network; however, [suberic acid]‚[4-bph] (4), produced unexpectedly by hydrothermal synthesis, displays a 3-D framework expanding from 2-D layers, in which N,N′-bis(4-picolinoyl) hydrazine (4-bph) is generated in situ from the hydrolysis of 4-bpo. [Benzene-1,4-dioxyacetic acid]‚[3-bpo] (5) takes on a nearly planar 2-D sheet, while [benzene-1,4-dioxyacetic acid]‚[4-bpo] (6) presents an unusual bilayered structure. For all binary compounds except 1, the acid-base components are connected by the carboxyl/pyridyl heterosynthon [O-H‚‚‚N and C-H‚‚‚O, R 2 2 ( 7)], which has been well exploited to engineer plenty of ordered crystalline architectures, to generate linear or zigzag tapes. Via subsidiary C-H‚‚‚O and/or N-H‚‚‚O (only for 4) hydrogen bonds between the neighboring tapes, these 1-D arrays are further extended to diverse networks from 2-D to 3-D. The similarities/differences between the hydrogen-bonded motifs of the cocrystals based on the flexible (alkyl) and rigid (aromatic) dicarboxylic acids with the same bent dipyridyl bases are also discussed, which may further enhance the crystal engineering of organic solids.

A new two-dimensional polyoxoniobate built by Lindqvist-type polyoxoanion and copper coordinated cations K2[Cu(H2O)6]{[Nb6O19][Cu(NH3)]2}·8H2O

“…To our knowledge, the diffusion technique is extensively used and provides an effective method for crystal growth in supramolecule chemistry and coordination chemistry [36][37][38], but it is rarely utilized in synthesizing POMs. Recently, our group has proved that the diffusion technique is an effective method for crystal growth in Nb-POM chemistry [32,33].…”

Noncovalent-bonded 1D–3D supramolecular architectures from 2-methylquinoline/quinoline with monocarboxylic acid and dicarboxylic acid

“…It should be noted that these structures are normally held together by the hydrogen-bonding synthons, and in this regard, the most frequently used moieties with hydrogen-bonding capability are pyridyl and carboxyl. Strong and specific recognition of the carboxylic acid group with pyridine (acid-pyridine synthon) is well studied [12][13][14][15][16]. There also some documents concerning quinoline/carboxylic acid co-crystals [17].…”

The Role of the Coordination Modes of a Flexible Bis(pyridylamide) Ligand in the Topology of 2D Copper(II) Complexes

“…Recently, using the rigid bis-pyridyl-bis-amide ligand 4-bpcb [4-bpcb = N,N -bis(4-pyridylamide)-1,4-benzene], we have obtained a novel threedimensional metal-organic coordination polymer [Cu 3 (4-bpcb) 3 (BTC) 2 ] 3 · ∼12H 2 O, in which discrete (H 2 O) 12 clusters are dispersed in the three-fold interpenetrating 3D metal-organic framework [18]. With the semi-rigid isomeric bipyridyl ligands bis(3-pyridylformyl)piperazine (3-bpfp) and bis(4-pyridylformyl)piperazine (4-bpfp) and with aromatic polycarboxylate ligands 1,3-H 2 BDC (1,3-H 2 BDC = 1,3-benzenedicarboxylic acid) or 1,3,5-H 3 BTC (1,3,5-H 3 BTC = 1,3,5-benzenetricarboxylic acid) as the bridging ligands, our group has obtained two layered structures and a novel 3,5-connected binodal 3D topology [19].…”