Ethane-1,2-diaminium 4,5-dichloro­phthalate

In the structure of the title compound, C2H10N2 2+·C8H2Cl2O4 2−, the dications and dianions form hydrogen-bonded ribbon substructures which enclose conjoint cyclic R 2 1(7), R 1 2(7) and R 4 2(8) associations and extend down the c-axis direction. These ribbons inter-associate down b, giving a two-dimensional sheet structure. In the dianions, one of the carboxyl­ate groups is essentially coplanar with the benzene ring, while the other is normal to it [C—C—C—O torsion angles = 177.67 (12) and 81.94 (17)°, respectively]

4-Amino­pyridinium cis-2-carb­oxy­cyclo­hexane-1-carboxyl­ate

In the structure of the title molecular salt, C5H7N2 +·C8H11O4 −, the cis monoanions associate through short O—H⋯O hydrogen bonds in the carb­oxy­lic acid groups [graph set C(7)], forming zigzag chains which extend along the c axis. These are inter­linked through pyridinium and amine N—H⋯O hydrogen bonds, giving a three-dimensional network structure

4-(2-Hydroxy­ethyl)anilinium 3-carb­oxy-4-hydroxy­benzene­sulfonate monohydrate

In the structure of the title compound, C8H12NO+·C7H5O6S−·H2O, isolated from the reaction of 2-(4-amino­phen­yl)ethanol with 5-sulfosalicylic acid, the cations form head-to-tail hydrogen-bonded chains through C 1 1(9) anilinium N+—H⋯Ohydrox­yl inter­actions while the anions also form parallel but C 1 1(8)-linked chains through carboxylic acid O—H⋯Osulfonate inter­actions. These chains inter-associate through a number of N+—H⋯O and O—H⋯O bridging inter­actions, giving a two-dimensional array in the ab plane

Poly[di-μ-aqua-bis­(μ-2-amino-4-nitro­benzoato)dicaesium]

In the structure of title compound, [Cs2(C7H5N2O4)2(H2O)2]n, the asymmetric unit contains two independent Cs atoms comprising different coordination polyhedra. One is nine-coordinate, the other seven-coordinate, both having irregular configurations. The CsO9 coordination polyhedron comprises O-atom donors from three bridging water mol­ecules, one of which is doubly bridging, three from carboxyl­ate groups, and three from nitro groups, of which two are bidentate chelate bridging. The CsO6N coordination polyhedron comprises the two bridging water mol­ecules, one amine N-atom donor, one carboxyl­ate O-atom donor and four O-atom donors from nitro groups (two from the chelate bridges). The extension of the dimeric unit gives a three-dimensional polymeric structure, which is stabilized by both intra- and inter­molecular amine N—H⋯O and water O—H⋯O hydrogen bonds to carboxyl­ate O-atom acceptors, as well as inter-ring π–π inter­actions [minimum ring centroid–centroid separation = 3.4172 (15) Å]

Guanidinium quinoline-2-carboxyl­ate

In the structure of the guanidinium salt of quinaldic acid, CH6N3 +·C10H6NO2 −, the asymmetric unit contains two independent cations and anions having similar inter-species hydrogen-bonding environments, which include cyclic R 2 2(8), R 2 1(6) and R 1 2(5) associations. These and additional weak aromatic ring π–π inter­actions [minimum ring-centroid separation = 3.662 (2) Å] give a two-dimensional layered structure

1,1,3,3-Tetra­ethyl­isoindolin-2-ium chloride

In the title compound, C16H26N+·Cl−, the cations and anions form discrete centrosymetric cyclic dimers through N—H⋯Cl hydrogen-bonding associations with graph-set R 4 2(8)

Guanidinium 3-nitro­benzoate

The title compound, CH6N3 +·C7H4NO4 −, an anhydrous guanidinium salt, shows a N—H⋯O hydrogen-bond network in which the guanidinium cation is involved in three cyclic R 2 1(6) hydrogen-bonding associations with separate carboxyl­ate O-atom acceptors. Further peripheral associations include a cyclic R 1 2(4) cation–anion inter­action, forming inter­linked undulating sheets in the three-dimensional structure

Sodium 2-nitro­cinnamate dihydrate: a one-dimensional hydrogen-bonded coordination polymer

The title compound catena-poly[aqua­sodium-μ2-aqua-μ3-2-nitro­cinnamato], [Na(C9H6NO4)(H2O)2]n, the sodium salt of trans-2-nitro­cinnamic acid, is a one-dimensional coordination polymer based on six-coordinate octa­hedral NaO6 centres, comprising three facially related monodentate carboxyl­ate O-atom donors from separate ligands (all bridging) [Na—O = 2.4370 (13)–2.5046 (13) Å], and three water mol­ecules (two bridging and one monodentate) [Na—O = 2.3782 (13)–2.4404 (17) Å]. The structure is also stabilized by intra-chain water–carboxyl­ate and water–nitro O—H⋯O hydrogen bonds

2,4-Diiodo­aniline

The structure of the title compound, C6H5I2N, shows a weak inter­molecular amine–amine N—H⋯N hydrogen-bonding inter­action, giving a helical chain which extends along the a axis. An intra­molecular N—H⋯I hydrogen bond is also observed

Guanidinium 2-phenyl­acetate

In the structure of the title salt, CH6N3 +·C8H7O2 −, the guanidinium cation gives three cyclic hydrogen-bonding inter­actions with O-atom acceptors of three independent phenyl­acetate anions, one R 2 2(8) and two R 2 1(6), giving one-dimensional columnar structures which extend down the 42 axis in the tetra­gonal cell. Within these structures, there are solvent-accessible voids of volume 86.5 Å3