The supramolecular structure of a cadmium complex with the new functionalized terpyridine ligand 4'-[4-(pyrimidin-5-yl)phenyl]-2,2':6',2''-terpyridine (L1): aqua(L1-κ³N,N',N'')(nitrato-κ²O,O')(nitrato-κO)cadmium(II) dihydrate.

The monomeric title compound, aqua(nitrato-κ²O,O')(nitrato-κO){4'-[4-(pyrimidin-5-yl)phenyl]-2,2':6',2''-terpyridine-κ³N,N',N''}cadmium(II) dihydrate, [Cd(NO3)2(C25H17N5)(H2O)]·2H2O, consists of a seven-coordinated CdII centre bound to the novel 4'-[4-(pyrimidin-5-yl)phenyl]-2,2':6',2''-terpyridine (L1) ligand (behaving as a tridentate chelate), two nitrate anions (as chelating-bidentate and monodentate ligands) and a water O atom. Both chelating groups define the base of a slightly deformed pentagonal bipyramid, while the monocoordinated ligands occupy the apices. The four heterocycles in L1 form a planar skeleton, while the central benzene ring is rotated from this planar geometry by more than 30°, probably because of packing effects. Noncovalent interactions lead to the formation of columnar arrays parallel to [100].

Monodentate and bridging behaviour of the sulfur-containing ligand 4'-[4-(methylsulfanyl)phenyl]-4,2':6',4''-terpyridine in two discrete zinc(II) complexes with acetylacetonate.

The Zn complexes bis(acetylacetonato-κ(2)O,O')bis{4'-[4-(methylsulfanyl)phenyl]-4,2':6',4''-terpyridine-κN(1)}zinc(II), [Zn(C(5)H(7)O(2))(2)(C(22)H(17)N(3)S)(2)], (I), and {µ-4'-[4-(methylsulfanyl)phenyl]-4,2':6',4''-terpyridine-κ(2)N(1):N(1'')}bis[bis(acetylacetonato-κ(2)O,O')zinc(II)], [Zn(2)(C(5)H(7)O(2))(4)(C(22)H(17)N(3)S)], (II), are discrete entities with different nuclearities. Compound (I) consists of two centrosymmetrically related monodentate 4'-[4-(methylsulfanyl)phenyl]-4,2':6',4''-terpyridine (L1) ligands binding to one Zn(II) atom sitting on an inversion centre and two centrosymmetrically related chelating acetylacetonate (acac) groups which bind via carbonyl O-atom donors, giving an N(2)O(4) octahedral environment for Zn(II). Compound (II), however, consists of a bis-monodentate L1 ligand bridging two Zn(II) atoms from two different Zn(acac)(2) fragments. Intra- and intermolecular interactions are weak, mainly of the C-H···π and π-π types, mediating similar layered structures. In contrast to related structures in the literature, sulfur-mediated nonbonding interactions in (II) do not seem to have any significant influence on the supramolecular structure.

Structural characterization of a hybrid terpyridine-pyrazine ligand and its one-dimensional ZnII coordination polymer: a computational approach to conventional and nonconventional intermolecular interactions.

The structures of a new hybrid terpyridine-pyrazine ligand, namely 4'-[4-(pyrazin-2-yl)phenyl]-4,2':6',4''-terpyridine (L2), C25H17N5, and its one-dimensional coordination polymer catena-poly[[bis(acetylacetonato-κ2O,O')zinc]-µ-4'-[4-(pyrazin-2-yl-κN4)phenyl]-4,2':6',4''-terpyridine-κN1], [Zn(C5H7O2)2(C25H17N5)]n or [Zn(acac)2(L2)]n (Hacac is acetylacetone), are reported. Packing interactions in both crystal structures are analyzed using Hirshfeld surface and enrichment ratio techniques. For the simpler structure of the monomeric ligand, further studies on the interaction hierarchy using the energy framework approach were made. The result was a complete picture of the intermolecular interaction landscape, which revealed some subtle details, for example, that some weak (at first sight negligible) C-H...N interactions in the structure of free L2 play a relevant role in the crystal stabilization.

The enrichment ratio of atomic contacts in the crystal structure of isomeric, triply protonated, 4'-functionalized terpyridine cations with [ZnCl4]2- as counter-ion.

We report herein the synthesis, crystallographic analysis and a study of the non-covalent inter-actions observed in the new 4'-substituted terpyridine-based derivative bis-[4'-(isoquinolin-2-ium-4-yl)-4,2':6',4''-terpyridine-1,1''-diium] tris-[tetra-chlorido-zincate(II)], (C24H19N4)2[ZnCl4]3 or (44TPH3)2[ZnCl4]3, where (44TPH3)3+ is the triply protonated cation 4'-(isoquinolinium-4-yl)-4,2':6',4'' terpyridinium. The compound is similar in its formulation to the recently reported 2,2':6',2'' terpyridinium analogue {bis-[4'-(isoquinolin-2-ium-4-yl)-2,2':6',2''-terpyridine-1,1''-diium] tris-[tetra-chlorido-zincate(II)] monohydrate; Granifo et al. (2017 ▸). Acta Cryst. C73, 1121-1130}, although rather different and much simpler in its structural features, mainly in the number and type of non-covalent inter-actions present, as well as in the supra-molecular structure they define.

Crystallographic and computational study of a network composed of [ZnCl4]2- anions and triply protonated 4'-functionalized terpyridine cations.

We report herein the synthesis, crystallographic analysis and a study of the noncovalent interactions observed in the new 4'-substituted terpyridine-based derivative bis[4'-(isoquinolin-2-ium-4-yl)-2,2':6',2''-terpyridine-1,1''-diium] tris[tetrachloridozincate(II)] monohydrate, (C24H19N4)2[ZnCl4]3·H2O or (ITPH3)2[ZnCl4]3·H2O, where (ITPH3)3+ is the triply protonated cation derived from 4'-(isoquinolin-4-yl)-2,2':6',2''-terpyridine (ITP) [Granifo et al. (2016). Acta Cryst. C72, 932-938]. The (ITPH3)3+ cation presents a number of interesting similarities and differences compared with its neutral ITP relative, mainly in the role fulfilled in the packing arrangement by the profuse set of D-H...A [D (donor) = C, N or O; A (acceptor) = O or Cl], π-π and anion...π noncovalent interactions present. We discuss these interactions in two different complementary ways, viz. using a point-to-point approach in the light of Bader's theory of Atoms In Molecules (AIM), analyzing the individual significance of each interaction, and in a more `global' analysis, making use of the Hirshfeld surfaces and the associated enrichment ratio (ER) approach, evaluating the surprisingly large co-operative effect of the superabundant weaker contacts.

Structural and theoretical characterization of a new twisted 4'-substituted terpyridine compound: 4'-(isoquinolin-4-yl)-2,2':6',2''-terpyridine.

4'-Substituted derivatives of 2,2':6',2''-terpyridine with N-containing heteroaromatic substituents, such as pyridyl groups, might be able to coordinate metal centres through the extra N-donor atom, in addition to the chelating terpyridine N atoms. The incorporation of these peripheral N-donor sites would also allow for the diversification of the types of noncovalent interactions present, such as hydrogen bonding and π-π stacking. The title compound, C24H16N4, consists of a 2,2':6',2''-terpyridine nucleus (tpy), with a pendant isoquinoline group (isq) bound at the central pyridine (py) ring. The tpy nucleus deviates slightly from planarity, with interplanar angles between the lateral and central py rings in the range 2.24 (7)-7.90 (7)°, while the isq group is rotated significantly [by 46.57 (6)°] out of this planar scheme, associated with a short Htpy...Hisq contact of 2.32 Å. There are no strong noncovalent interactions in the structure, the main ones being of the π-π and C-H...π types, giving rise to columnar arrays along [001], further linked by C-H...N hydrogen bonds into a three-dimensional supramolecular structure. An Atoms In Molecules (AIM) analysis of the noncovalent interactions provided illuminating results, and while confirming the bonding character for all those interactions unquestionable from a geometrical point of view, it also provided answers for some cases where geometric parameters are not informative, in particular, the short Htpy...Hisq contact of 2.32 Što which AIM ascribed an attractive character.

Structure of a dinuclear cadmium complex with 2,2'-bi-pyridine, monodentate nitrate and 3-carb-oxy-6-methyl-pyridine-2-carboxyl-ate ligands: intra-molecular carbon-yl(lone pair)⋯π(ring) and nitrate(π)⋯π(ring) inter-actions.

The centrosymmetric dinuclear complex bis-(µ-3-carb-oxy-6-methyl-pyridine-2-carboxyl-ato)-κ(3) N,O (2):O (2);κ(3) O (2):N,O (2)-bis-[(2,2'-bi-pyridine-κ(2) N,N')(nitrato-κO)cadmium] methanol monosolvate, [Cd2(C8H6NO4)2(NO3)2(C10H8N2)2]·CH3OH, was isolated as colourless crystals from the reaction of Cd(NO3)2·4H2O, 6-methyl-pyridine-2,3-di-carb-oxy-lic acid (mepydcH2) and 2,2'-bi-pyridine in methanol. The asymmetric unit consists of a Cd(II) cation bound to a µ-κ(3) N,O (2):O (2)-mepydcH(-) anion, an N,N'-bidentate 2,2'-bi-pyridine group and an O-mono-dentate nitrate anion, and is completed with a methanol solvent mol-ecule at half-occupancy. The Cd complex unit is linked to its centrosymmetric image through a bridging mepydcH(-) carboxyl-ate O atom to complete the dinuclear complex mol-ecule. Despite a significant variation in the coordination angles, indicating a considerable departure from octa-hedral coordination geometry about the Cd(II) atom, the Cd-O and Cd-N distances in this complex are surprisingly similar. The crystal structure consists of O-H⋯O hydrogen-bonded chains parallel to a, further bound by C-H⋯O contacts along b to form planar two-dimensional arrays parallel to (001). The juxtaposed planes form inter-stitial columnar voids that are filled by the methanol solvent mol-ecules. These in turn inter-act with the complex mol-ecules to further stabilize the structure. A search in the literature showed that complexes with the mepydcH(-) ligand are rare and complexes reported previously with this ligand do not adopt the µ-κ(3) coordination mode found in the title compound.

A temperature-induced order-disorder phase transition in a 4-substituted 4,2':6',4''-terpyridine.

Crystals of 4'-(isoquinolin-4-yl)-4,2':6',4''-terpyridine (iqtp), C24H16N4, grown from an ethanol solution, undergo a reversible first-order single-crystal to single-crystal phase transition at Tc in the range 273-275 K, from a disordered higher-temperature phase [form (I)] in the space group P21/c, with one single molecule in the asymmetric unit, to an ordered lower-temperature one [form (II)] in the space group P21/n, with two independent molecules in the asymmetric unit. There is a group-subgroup relationship linking (I)-(II), due to cell doubling and the disappearance of a number of symmetry operations. In addition to X-ray diffraction, the transition has been monitored by Raman spectroscopy and differential scanning calorimetry, the latter disclosing an enthalpy change of 0.72 (6) kJ mol(-1). Variations of the unit-cell parameters with temperature between 170 and 293 K are presented. The evolution of diffraction spots in the vicinity of the transition temperature shows the coexistence of both phases, confirming the first-order character of the transition. Structural details of both phases are analyzed and intermolecular interactions compared in order to investigate the mechanism of the phase transition. A three-dimensional Hirshfeld surface analysis was performed to corroborate the significant changes in the intermolecular features.

Poly[[aquabis(mu(2)-isonicotinato-kappa(3)N:O,O')cadmium(II)] 1,4-di-3-pyridyl-2,3-diaza-1,3-butadiene hemisolvate].

The title compound, {[Cd(C(6)H(4)NO(2))(2)(H(2)O)] x 0.5C(12)H(10)N(4)}(n), presents an intricate three-dimensional network with cavities traversing it in three orthogonal directions, where the (disordered) guest molecules lodge. The compound is a member of a series of coordination polymers presenting the same main host framework but with guests of variable size and geometry, to which the flexible skeleton seems to adapt. The disorder in the structure is explained in terms of an apparently well defined specificity in the position/orientation of the guest molecules, as determined by the main framework.

Two one-dimensional zinc(II) coordination polymers: catena-poly[[bis(pentane-2,4-dionato-kappa2O,O')zinc]-mu-1,4-bis(x-pyridyl)-2,3-diazabuta-1,3-diene] (x = 3, 4).

The structures of the two title isomeric compounds, [Zn(C5H7O2)2(C12H10N4)]n, are built up around two non-equivalent symmetry centres, one of them at the cation position and the other bisecting the N-N bond in the 1,4-bis(3/4-pyridyl)-2,3-diazabuta-1,3-diene (3pdb/4pdb) units. Both Zn cations have the Zn atoms an inversion centres and present tetragonally distorted octahedral environments, but differences in their linkage through the 3pdb and 4pdb ligands give rise to differently shaped weakly interacting chains.

Catena-poly[[bis(hexafluoroacetylacetonato-kappa2O,O')zinc(II)]-micro-4,4'-bipyridine-kappa2N:N'].

The structure of the title compound, catena-poly[[bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato-kappa(2)O,O')zinc(III)]-micro-4,4'-bipyridine-kappa(2)N:N'], [Zn(C(5)HF(6)O(2))(2)(C(10)H(8)N(2))](n), consists of polymeric chains, running in two perpendicular directions, organized as planes normal to the tetragonal axis. The elemental unit of the chains is the zinc(II) coordination polyhedron bisected by a twofold symmetry axis, and thus only half of the unit is independent. The octahedral coordination geometry of the metal centre is composed of two oxygen-chelating (symmetry-related) hexafluoroacetylacetonate groups and two translationally related 4,4'-bipyridine groups, which act as connecting agents in the polymer structure. The stabilization of this architecture of chains and planes is associated with a number of weak C-H.O and C-H.F hydrogen bonds.