Offset-face-to-face Research Articles

Structures, Characterization and DFT Studies of Four Novel Nickel Phenanthroline Complexes

Four Ni–phen complexes were prepared and characterized by FTIR and thermal analysis. The X-ray structure determination shows that the geometry around NiII ions in complexes 1, [Ni(phen)2(H2O)(ONO2)](NO3); 2, [Ni(phen)2(H2O)Cl]Cl; 3, [Ni(phen)(CH3CN)(ONO2)(O2NO)] and 4, [Ni(phen)3](NO3)2.H2O.C2H5OH is considerably distorted octahedral. The coordination core geometries in 1, 2, 3 and 4 are NiN4O2, NiN4OCl, NiN3O3 and NiN6, respectively. The crystal packing and crystal supramolecularity analysis of the complexes reveal the importance of aryl∙∙∙aryl interactions, and both offset face-to-face (OFF) and edge-to-face (EF) motifs are dominant. Hydrogen bonding interactions in these structures reinforce aryl∙∙∙aryl interactions. FTIR proved the coordination of M-N and M-Cl as well as the presence of nitro groups in the complexes, while thermal analysis revealed that the loss of water, chloro and nitro groups occurred before the degradation of phenanthroline ligand in the complexes. DFT study indicates that a strong correlation exists among theoretical and experimentally determined geometric parameters with distorted octahedral geometry. The charge density in HOMO is localized on the metal halogen bond and nitrate group (NO3−), whereas the LUMO cloud density is mainly distributed on the phen ring, which indicates the electroactive nature of the ring.

Interactions of Substituted Nitroaromatics with Model Graphene Systems: Applicability of Hammett Substituent Constants To Predict Binding Energies.

Applicability of Hammett parameters (σm and σp) was tested in extended π-systems in gas phase. Three different model graphene systems, viz. 5,5-graphene (GR), 3-B-5,5-graphene (3BGR), and 3-N-5,5-graphene (3NGR), were designed as extended π-systems, and interactions of various nitrobenzene derivatives (mainly m- and p-substituted together with some multiple substitutions) on such platforms were monitored using density functional theory (M06/cc-pVDZ, M06/cc-pVTZ, M06/sp-aug-cc-pVTZ) and Møller–Plesset second-order perturbation (MP2/cc-pV-DZ) theory. Offset face to face (OSFF) stackings were found to be the favored orientations, and reasonable correlations were found between binding energies (ΔEB) and the ∑|σm| values of the substituted nitrobenzenes. It was proposed previously that |σm| contains information about the substituents’ polarizability and controls electrostatic and dispersion interactions. The combination of ∑|σm| and molar refractivity (as ∑Mr) or change in polarizability (Δα: with respect to benzene) of nitrobenzene derivatives generated statistically significant correlation with respect to ΔEB, thereby supporting the hypothesis related to the validity of |σm| correlations. The |σp| parameters also maintain similar correlations for the various p-substituted nitrobenzene derivatives together with several multiply-substituted nitrobenzene derivatives. The correlation properties in such cases are similar to the |σm| cases, and the energy partition analysis for both the situations reveled importance of electrostatic and dispersion contributions in such interactions. The applicability of Hammett parameters was observed previously on the restricted parallel face to face orientation of benzene···substituted benzene systems, and the present results show that such an idea could be used to predict ΔEB values in OSFF orientations, if the scaffolds are designed in such a way that substituted benzene systems cannot escape their π-clouds.

Four supramolecular isomers of dichloridobis(1,10-phenanthroline)cobalt(II): synthesis, structure characterization and isomerization.

Crystal engineering can be described as the understanding of intermolecular interactions in the context of crystal packing and the utilization of such understanding to design new solids with desired physical and chemical properties. Free-energy differences between supramolecular isomers are generally small and minor changes in the crystallization conditions may result in the occurrence of new isomers. The study of supramolecular isomerism will help us to understand the mechanism of crystallization, a very central concept of crystal engineering. Two supramolecular isomers of dichloridobis(1,10-phenanthroline-κ(2)N,N')cobalt(II), [CoCl2(C12H8N2)2], i.e. (IA) (orthorhombic) and (IB) (monoclinic), and two supramolecular isomers of dichloridobis(1,10-phenanthroline-κ(2)N,N')cobalt(II) N,N-dimethylformamide monosolvate, [CoCl2(C12H8N2)2]·C3H7NO, i.e. (IIA) (orthorhombic) and (IIB) (monoclinic), were synthesized in dimethylformamide (DMF) and structurally characterized. Of these, (IA) and (IIA) have been prepared and structurally characterized previously [Li et al. (2007). Acta Cryst. E63, m1880-m1880; Cai et al. (2008). Acta Cryst. E64, m1328-m1329]. We found that the heating rate is a key factor for the crystallization of (IA) or (IB), while the temperature difference is responsible for the crystallization of (IIA) or (IIB). Based on the crystallization conditions, isomerization behaviour, the KPI (Kitajgorodskij packing index) values and the density data, (IB) and (IIA) are assigned as the thermodynamic and stable kinetic isomers, respectively, while (IA) and (IIB) are assigned as the metastable kinetic products. The 1,10-phenanthroline (phen) ligands interact with each other through offset face-to-face (OFF) π-π stacking in (IB) and (IIB), but by edge-to-face (EF) C-H...π interactions in (IA) and (IIA). Meanwhile, the DMF molecules in (IIB) connect to neighbouring [CoCl2(phen)2] units through two C-H...Cl hydrogen bonds, whereas there are no obvious interactions between DMF molecules and [CoCl2(phen)2] units in (IIA). Since OFF π-π stacking is generally stronger than EF C-H...π interactions for transition-metal complexes with nitrogen-containing aromatic ligands, (IIA) is among the uncommon examples that are stable and densely packed but that do not following Etter's intermolecular interaction hierarchy.

Synthesis of a new two-dimensional Cd(II) coordination compound by benzotriazole-5-carboxylate acid and 1,10-phenanthroline and its crystal structure and characterization

A mixed-ligand metal-organic complex [Cd(C7H3N3O2)(C12H8N2)] n was synthesized by cadmium(II) nitrate, 1,10-phenanthroline(phen) and benzotriazole-5-carboxylate acid(H2btca). Single crystal X-ray analysis indicates that complex 1 has a two-dimensional layer structure and crystallizes in an orthorhombic space group(Pbca), with cell parameters, a=1.7422(6) nm, b=0.9264(3) nm, c=2.0729(7) nm, α=90°, β=90°, γ=90°, V=3.346(2) nm3, Z=8. Each central Cd(II) is six-coordinated by four N atoms, two of which are from 1,10-phenanthroline, and the other two from two different triazole nitrogen atoms and two O atoms from benzotriazole-5-carboxylate, forming a distorted octahedral geometry. Adjacent Cd(II) centers are bridged by benzotriazole-5-carboxylate molecules to form a one-dimensional chain, which is further connected by the nitrogen atoms of btca2− to form an extended two-dimensional wave-like layer, with OFF(offset face-to-face) stacking interactions between phen ligands in adjacent layers, which are helpful to forming the three-dimensional supramolecular structure.

Quaterphenylterpyridine: Synthesis and Metal‐Ion Complexation

AbstractA quaterphenylterpyridine ligand (qptpy) with the rodlike quaterphenyl unit attached in the 4′‐position has been synthesised by a Pd‐catalysed Suzuki cross‐coupling reaction. A crystal structure determination on the complex [Zn(qptpy)Cl2]·dmf (dmf = dimethylformamide) has shown the ligand to be bound in the expected N3‐tridentate manner to the essentially trigonal‐bipyramidal dichloro metal ion, with the quaterphenyl substituents involving a twisted array of the separate phenyl groups and the shortest contacts between aromatic groups involving just the polar terpyridine head groups to give an infinite, offset face‐to‐face (OFF) π‐stacking array. A comparison is made with the structures of the bis(ligand) complexes of Zn(ClO4)2 and Cd(ClO4)2 with the bromobiphenylterpyridine ligand (Brbptpy) synthesised as an intermediate for the formation of qptpy. A study of the absorption and emission spectra of qptpy and a range of its metal‐ion complexes has shown that the ligand provides a ratiometric fluorescence response for both ZnII and CdII.

Alternative metal grid structures formed by [M(terpy)2]2+ and [M(terpyOH)2]2+ complexes with small and large tetrahedral dianions, and by [Ru(terpy)2

Terpy embraces (TE) are intermolecular motifs involving metal complexes of the type [M(terpy)2]2+ (terpy = 2,2′:6′,2″-terpyridine), based on concerted offset-face-to-face (OFF) and edge-to-face (EF) interactions between pyridyl rings. These embraces are well known to occur as extended two-dimensional grid motifs in crystals (called two-dimensional terpy embraces, 2D-TE). We have previously enunciated the layer-stacking principles for 2D-TE when the complexes are associated with monoanions which occupy cavities within grooves on the surfaces of the layers. We introduce here two new features of terpy embraces in crystals: (a) the use of tetrahedral dianions to control the stacking of layers and (b) an alternative layer motif, namely the two-dimensional inverted chain terpy embrace (2D-IC-TE). The standard 2D-TE is constructed with only translation of complexes, while the 2D-IC-TE also possesses inversion centres between complexes in the layer. The density of local OFF and EF interactions in the new 2D-IC-TE is the same as that in the standard 2D-TE, but the surfaces of the layers possess a halved number of enlarged troughs. In crystal [Ni(terpy)2](SO4)(nPrOH)4, 1, the orthogonal SO2 fins of dianionic sulfate engage the shallow grooves of the standard 2D-TE grids of [Ni(terpy)2]2+ complexes, causing them to stack in a fashion not previously observed. With a larger tetrahedral dianion, HgI42−, in crystal [Ni(terpy)2](HgI4), 2, the alternative 2D-IC-TE grids of [Ni(terpy)2]2+ complexes occur, with the anions occupying the troughs. Variation of the ligand to terpyOH (4-hydroxy-2,2′:6′,2″-terpyridine), with sulfate, yields crystals [Ni(terpyOH)2](SO4)(MeOH)(EtOH)(H2O)0.5, 3, which also contain 2D-IC-TE grids. Half of the sulfate together with methanol and ethanol occupy the troughs, and a hydrogen bonding network links terpyOH, MeOH, EtOH, SO42− and water. Two related crystal structures, [CoIII(terpyOH)(terpyO)](SO4)(EtOH)3(H2O)4, 4, and [CoIII(terpyOH)(terpyO)](BF4)2(H2O)4.5, 5, are also described. They are dominated by hydrogen bonding networks, and contain no terpy embraces. The one known related structure with no anions, [Ru(terpy)2]0 [CSD LOCRIE], is also analysed in detail for the first time. It contains modified 2D-IC-TE layers, interleaved with twinned pairs of one-dimensional TE chains. There are multiple OFF and EF interactions at the interfaces of these two motifs, but no new concerted embrace motifs. Analysis of this structure in the context of conventional [M(terpy)2]2+ complexes provides some guidance for the engineering of two-dimensional grids.

A layered iodocuprate based on a 3D cationic supramolecular network of dimeric Co(ii) complexes by offset face-to-face interactions

A novel iodocuprate, [Co(phen)2(µ-Cl)]2[Cu9I11H2O]n (phen = 1,10-phenanthroline), composed of a two-dimensional (2D) corrugated anionic layer [Cu9I11H2O]n2− and a three-dimensional (3D) cationic supramolecular network, has been solvothermally obtained. The anionic layer [Cu9I11H2O]n2− in the bc plane can be considered as being built up by two types of secondary building units (SBUs) Cu4I9 and Cu10I14(H2O)2. The dimeric [Co(phen)2(µ-Cl)]22+ interacts with each other via offset face-to-face (OFF) interactions giving rise to a 3D cationic supramolecular network with cristobalite topology, which appears to have a complementary relationship with inorganic anionic layers.

The co-crystal of iron(II) complex hydrate with hydroxybenzoic acid: [Fe(Phen)3]Cl(p-hydroxybenzoate).2(p-hydroxybenzoic acid).7H2O

Crystal of [Fe(Phen)3]Cl(PHB).2(PHBH).7H2O (1) is triclinic, space group P-1 with a = 12.0388(11) A, b = 15.5286(14) A, c = 15.7794(14) A, α = 89.759(2)°, β = 75.818(2)°, γ = 71.900(2)° and Z = 2, (phen = phenanthroline, PHBH = p-hydroxybenzoic acid, PHB = p-hydroxybenzoate anion). The phen in adjacent Fe(phen)3 2+ cations are π–π interacted forming offset face to face (OFF) motifs. Juxtaposition of four phen ligands from two cations encapsulate an R2 2(8) dimeric unit of H-bonded PHBH molecules within a centrosymmetric box froming a filled aryl box motif (FAB). Alternation of OFF and FAB motifs form {OFF⋯FAB}∞ strands. The Fe(phen)3 2+ cation engages its phen ligands in π–π and/or CH–π interactions with two crystalographically different PHBH molecules and one PHB anion. Seven water molecules and a chloride anion per iron(II) trisphenanthroline cation fill empty spaces in the structure forming a hydrophilic cluster. Extensive intermolecular H-bond interactions occur between water molecules, chloride anions, PHBH molecules, and PHB anions. Thermal analysis of (1) was done under N2(g). The TG, and dTG curves revealed the expected mass losses. All associated processes are endothermic as shown in the DSC curve.

The crystal structure of (Ph4P)2[Hg2(SPh)6]: Synthesis, characterization and structure supramolecularity

X-ray analysis at ambient temperature has established the crystal structure of the monoclinic (Ph4P)2[Hg2(SPh)6]. It contains the bitetrahedral [(PhS)2Hg(μ-SPh)2Hg(SPh)2]2− anionic complex, in contrast to most mercury thiolate complexes, which contain the distorted-trigonal [Hg(SPh)3]− species. The crystal supramolecularity was analysed in the context of the issue of Ph ··· Ph (phenyl ··· phenyl) supramolecular synthons and the relative energies of intraionic and interionic interactions. The crystal lattice is dominated by the Ph ··· Ph supramolecular synthons, containing parallel chains of Ph4P+ ions and stacks of [Hg2(SPh)6]2− ions. Each chain of cations contains alternating 6PE (sixfold phenyl embrace) and P4PE (parallel fourfold phenyl embrace) motifs, with a repeat distance. The canting of [Hg2(SPh)6]2− ions relative to their stack axis is correlated with the repeat length of the cation chains, with EF (edge-to-face) and OFF (offset-face-to-face) Ph ··· Ph interactions between Ph4P+ and [Hg2(SPh)6]2−. The strength and directionality of these supramolecular synthons are evident in the calculated through-space energies (−16.7 kJ mol−1 per two Ph4P+ ions engaged in a P4PE and −42.3 kJ mol−1 per two Ph4P+ ions engaged in a 6PE).

Crystal packing principles for ferrocenyl groups linked by polyyne chains: dimorphism of Fc-C4-Fc

The crystal structure and packing of a new dimorph (2B) of 1,4-diferrocenyl-1,3-butadiyne (Fc-C4-Fc, 2) is described and analysed, and compared with the different crystal packing of dimorph 2A. This analysis is made in the context of the polymorphic crystal packing of ferrocene (1), and the crystal packing of 1,8-diferrocenyl-octatetrayne, Fc-C4-Fc. In 2B the packing is layered, allowing the Fc groups to be organised in approximately square arrays of well-developed edge-to-face (EF) motifs, very similar to the arrangement in the monoclinic and triclinic polymorphs of ferrocene. The C4 chains are sandwiched between the Fc layers in 2B. The same molecule in 2A is packed with some offset-face-to-face (OFF) motifs between Fc groups, and with a motif in which C4 chains occupy the grooves between cyclopentadienyl rings of Fc. In FcC8Fc the packing is dominated by the C8 chains, surrounded by six molecules, two of which present cyclopentadienyl faces to the C8 chain, and four present the groove in the ferrocenyl group, with no EF or OFF motifs. In this progression of structure types and intermolecular motifs for molecules Fc-Cn-Fc, the members with C4 occur at the transition between the ferrocenyl dominant intermolecular motifs and the Cn chain dominant features. Dimorph 2A is like the longer chain structure, while 2B is like ferrocene.

Dimorphic intra- and intermolecular aryl motifs in symmetrical hexafaceted molecules (ArnX)3Y-Z-Y(XArn)3.

A variety of crystals containing molecules formulated generally as (ArnX)3Y-Z-Y(XArn)3 with exact or pseudo S6 symmetry have been analysed for the presence of intra- and intermolecular multiple aryl embraces composed of offset-face-to-face (OFF) and edge-to-face (EF) local motifs. Ar is phenyl or substituted phenyl; n = 1, 2 or 3; the linkage Z is linear diatomic, linear monatomic, absent (Y-Y bond), or void (Y atoms unconnected). Representative molecular systems analysed are (PhCH2)3Si-O-Si(CH2Ph)3, (PhCH2)3Sn-Sn(CH2Ph)3, (4-Me-C6H4CH2)3Ge-O-Ge(CH2C6H4-4-Me)3, [(PhS)3Fe-O-Fe(SPh)3]-, [(PhCH2)3P-Cu-P(CH2Ph)3]+ and [(Ph3P)3Ag-CN-Ag(PPh3)3]+. One characteristic intramolecular motif is a sixfold phenyl embrace (6PE) in which aryl groups fold back to the central domain of the molecule forming a rhombohedral box maintained by (EF)6. When the aryl groups are in exo positions there is an (EF)3 motif, like a tractor wheel, at each end of the molecule: [(Ph2N)3Ti-O-Ti(NPh2)3] possesses both intramolecular motifs as (EF)3-(EF)6-(EF)3. The molecules in this set are hexafaceted, and the crystal packing is generally based on intermolecular EF or OFF motifs with these faces, either from the central (EF)6 set or the end (EF)3-(EF)3 sets. Three types of subtle crystal packing isomerism occur: 1) the faces of the rhombohedral boxlike molecules slide over each other with variation of the intermolecular motifs, forming dimorphic crystals in space groups R3 or P1; 2) the faces of the tractor wheels (EF)3 slide over each other or 3) very similar molecules crystallise with the rhombohedral box or tractor wheel structures. In general the molecules considered are shape auspicious rather than shape awkward; solvent is included in a small proportion of the crystals and the crystal packing in these compounds is evidently efficient. Some principles for elaboration of these systems and the design of molecular crystal lattices are considered.

Dimorphs of (Ph4P)2[Cd2(SPh)6]: Crystal Packing Analyses and the Interplay of Intermolecular and Intramolecular Energies

The crystallization and structure of a triclinic dimorph (1T) of (Ph4P)2[(PhS)2Cd(μ-SPh)2Cd(SPh)2] are reported and its crystallization conditions compared with those of the monoclinic dimorph 1M. The variations in molecular structure and crystal packing of both crystals are analyzed and compared, in the context of the issue of the relative influences and energies of intramolecular and intermolecular interactions. Both crystals contain parallel chains of Ph4P+ ions and stacks of [Cd2(SPh)6]2- ions. In 1T the cation chain is the classic zigzag infinite chain of 6-fold phenyl embraces (ZZI6PE), while in 1M the cation chain contains alternating 6PE and P4PE (parallel 4-fold phenyl embrace) motifs, with a longer repeat distance. The canting of [Cd2(SPh)6]2- ions relative to their stack axis is correlated with the repeat length of the cation chain, and there are EF (edge-to-face) and OFF (offset-face-to-face) phenyl···phenyl interactions between Ph4P+ and [Cd2(SPh)6]2-. The conformations of the SPh ligands dif...

High symmetry crystal supramolecularity: –XPh3 molecules in cubic latticesElectronic supplementary information (ESI) available: additional figures (Fig. S1–3) described in the text. See http://www.rsc.org/suppdata/nj/b1/b104324m/

The majority of molecular crystals in the Cambridge Structural Database involve relatively low symmetry molecules, engaged by intermolecular interactions with restricted symmetry, resulting in the preponderant occurrence of a small number of relatively low symmetry crystallographic space groups as expounded by Brock and Dunitz. We are examining some contrasting crystal structure types that contain higher symmetry molecules involved in high symmetry intermolecular motifs and generating high symmetry space groups. This paper considers molecules containing XPh3 groups, engaged in multiple phenyl embraces with local S6 () symmetry, generating crystal lattices with cubic symmetry. The conceptual framework for these analyses also involves the presence, symmetry, and occupancy of cavities in high symmetry lattices, with extensions to crystal trapping of unusual species such as [Cu2Br5]2− and [Cu8Br15]6−. The compounds included in the analyses of crystal packing and symmetry in this paper are (MePh3P+)2[Cu2Br5]2−, Ph3POGaCl3 , Ph3AsI2 , N(Ph-2-OMe)3 , Ph3SnCl, Ph3PAuCCAuPPh3·(C6H6)2 , Ph3PAu(B6H6)AuPPh3 , (Ph3PH+)2[SnCl6]2−, and (Ph3MeP+)6 [Cu8Br15]6−. Concerts of edge-to-face (EF) and offset-face-to-face (OFF) local interactions between phenyl groups generate bimolecular (EF)6 = 6PE with symmetry S6 , hexamolecular (EF)6 with symmetry S6 , trimolecular (EF)3 , hexamolecular (OFF)6 , and two-dimensional {(OFF)6}∞ . Crystal supramolecular analysis includes description of the asymmetric segments of intermolecular motifs, as well as the conventional asymmetric sector of the molecule.

High symmetry crystal supramolecularity: –XPh3 molecules in rhombohedral lattices, using multimolecular rather than bimolecular sixfold phenyl embraces

Molecules of the type Ph3XYXPh3 commonly crystallise in trigonal and rhombohedral lattices comprised of hexagonal arrays of sixfold phenyl embraces (HA6PE) which are bimolecular concerts of edge-to-face (EF) phenyl···phenyl interactions. In this paper we describe crystal structures containing molecules Ph3XYXPh3, also crystallising in the space group R characteristic of the HA6PE lattice, but without the bimolecular (EF)6 form of 6PE. Instead there are multimolecular concerts of EF and offset-face-to-face (OFF) motifs, building up hexagonal layers and in some cases generating high symmetry cavities. These crystals possess the same molecular symmetry as the HA6PE systems, and crystallise in the same space groups, but have different intermolecular motifs: they are effectively crystal supramolecular isomers of the HA6PE lattice. The specific crystalline compounds analysed are Ph3SiOSiPh3·C6H6, Ph3SiNCNSiPh3 and Ph3PNPPh3+[Nb(CO)6]−. The crystal packing in (MePh3P)2[Cu4I6], and in a high symmetry Ni3 complex crystallised with Ph3PO, both in space group Rc also characteristic of the HA6PE lattice, are supramolecular isomers of the HA6PE lattice because the bimolecular motif is (OFF)3 rather than (EF)6. The crystal packing analyses benefit by recognition of the asymmetric sectors of the intermolecular interactions and of cavities, in addition to the conventional asymmetric sectors of the molecular components.

The crystal supramolecularity of metal phenanthroline complexes

The 1,10-phenanthroline (phen) ligand in metal complexes commonly forms offset face-to-face (OFF) motifs, and less frequently edge-to-face (EF) motifs. An investigation of the 335 M(phen) complexes, 159 M(phen)2 complexes, and 33 M(phen)3 complexes in the Cambridge Structural Database has revealed that in crystals these primary OFF and EF motifs combine to form concerted motifs, and extended motifs, in a variety of ways. Stacks of phen ligands engaging OFF motifs on both faces are very common for complexes M(phen) and M(phen)2. Even more common for M(phen)2 are zigzag chains in which each phen ligand links to neighbours in the chain with an OFF motif. The parallel fourfold aryl embrace (P4AE, comprised of one OFF and two EF) occurs for complexes M(phen)2 and M(phen)3, with some variety in geometry between a single OFF at one extreme to (EF)2 at the other. This variability in the P4AE is a consequence of the larger surface area of the phen ligand, compared with those of 2,2′-bipyridyl (bipy) ligands or phenyl groups (which also form this motif), and has been evaluated by calculations of the supramolecular attractive energies. The P4AE associate further, maximising the use of phen surfaces, to form chains of P4AE, chains of P4AE·OFF, and compact two-dimensional nets propagated by both P4AE and OFF motifs. There are examples of three-dimensional nets using these motifs. There is a notable absence of sixfold aryl embraces (6AE, comprised of concerted (EF)6) amongst M(phen)3 complexes, and a clear difference with M(bipy)3 complexes where 6AEs are prevalent. Various M(phen)2 and M(phen)3 complexes pack in crystals to form tight hydrophobic domains, often as slabs, segregated from hydrophilic domains containing hydrogen bonding components and anions. The crystallisation and crystal packing of [Co(phen)3][BF4]2·H2O·EtOH, which exemplifies this pattern, are reported. The implications for crystal engineered enantioselection by [M(phen)3] complexes are discussed.

Crystal packing motifs for mixed oxalate/phenanthroline metal complexes

The preparations and crystal structures of (Ph4P)[Cr(phen)(ox)2](H2O) 1, [Co(phen)2(ox)](BF4) 2 and [Co(phen)2(ox)]I(H2O)2(EtOH)0.53 are described (phen⊕=⊕1,10-phenanthroline, ox⊕=⊕oxalate), and their crystal packing analysed in terms of the crystal supramolecular motifs and multiple aryl embraces. The crystal packing of 1 is determined by embrace motifs involving both the Ph4P+ cation and the anion [Cr(phen)(ox)2]−, principally an eight component concerted embrace (Ph4P+)·{[Cr(phen)(ox)2]−}2·(Ph4P+) comprised of three offset face-to-face (OFF) and six edge-to-face (EF) primary motifs. Complex 2 is dominated by well developed OFF-chain motifs for the phen ligands, reinforced by multiple C–H⋯O hydrogen bonds, to form a strongly hydrophobic lattice crystallising from water. Structure 3 crystallises with an efficient three-dimensional net using all three ligands of [Co(phen)2(ox)]+ in primary embrace motifs, with separate domains for the hydrogen bonded solvent molecules. The analyses identify crystal packing principles, especially the favourability of OFF phen embraces, the segregation of hydrophobic M(phen)n domains, and the prevalence of C–H⋯O hydrogen bonds involving oxalate or water. Predictions about crystal packing are made.

Crystal supramolecular motifs for [Ph4P]+ salts of [M(mnt)2]2−, [M(mnt)2]−, [{M(mnt)2}2]2−, [M(mnt)3]3− and [M(mnt)3]2− (mnt2− = maleonitriledithiolate) †

The crystal structures of [Ph4P]2[M(mnt)2] (M = Zn 1, Cu 2 or Ni 3), [Ph4P][M(mnt)2] (M = Cu 4 or Ni 5), [Ph4P]2[{M(mnt)2}2] (M = Co 6 or Fe 7), [Ph4P]2[M(mnt)3] (M = Fe 8 or Cr 10) and [Ph4P]3[Cr(mnt)3] 9 {mnt = maleonitriledithiolate, [S2C2(CN)2]2−} have been determined to investigate the packing and supramolecular motifs in crystals containing [Ph4P]+ cations and [M(mnt)n]z− anions. Seven different crystal packings are described. Crystals 2 are isomorphous with 3, as are 4 with 5, and 6 with 7, and two dimorphs of 8 were identified (orthorhombic α-8 and monoclinic β-8). The lattices of all compounds with planar (2, 3, 4, 5) or approximately planar (6, 7) anions contain segregated parallel stacks of anions (canted to the stack axis) and columns of embracing [Ph4P]+ cations. The structures of 2 and 3 contain approximately linear sequences of alternating sixfold phenyl embraces (6PE) and offset-face-to-face (OFF) motifs between cations, while the structures of 4, 5, 6 and 7 contain linear chains of cations engaged in translational fourfold phenyl embraces (4PE). Where the anions are not planar (tetrahedral 1 or octahedral 8–10), OFF interactions between planar subsections of the anions (i.e. mnt ligands) and planar subsections of the cations (i.e. phenyl rings) occur, as a concerted motif involving four ions (1), or as a new sandwich motif (α-8, β-8). This sandwich motif, Ph⋯mnt⋯Ph, occurs for one mnt ligand per anion in α-8, and two mnt ligands per anion in β-8. Calculated energies are reported. Weak C–H⋯S and C–H⋯N hydrogen bonds occur in all structures, and appear to control the details of the commensurability between chains of cations and stacks of anions. Edge-to-face (EF) motifs between phenyl rings and mnt ligands do not occur. All crystals except one (9) are devoid of solvent, implying an absence of shape awkwardness in crystals of this type. The crystal packing of the related compound [MePh3P][Ni(mnt)2] contains columns of stacked parallel fourfold phenyl embracing cations, parallel to stacked anions.