Side‐chain conformations in the isomorphous polyfluorinated {4,4′‐bis[(2,2‐difluoroethoxy)methyl]‐2,2′‐bipyridine‐κ2N,N′}dichloridopalladium and ‐platinum complexes

The polyfluorinated title compounds, [M Cl₂(C₁₆H₁₆F₄N₂O₂)] or [4,4′‐(HCF₂CH₂OCH₂)₂‐2,2′‐bpy]M Cl₂ [M = Pd, ( 1 ), and M = Pt, ( 2 )], have –C(H_α)₂OC(H_β)₂CF₂H side chains with H‐atom donors at the α and β sites. The structures of ( 1 ) and ( 2 ) are isomorphous, with the nearly planar (bpy)M Cl₂ molecules stacked in columns. Within one column, π‐dimer pairs alternate between a π‐dimer pair reinforced with C—H…Cl hydrogen bonds (α,α) and a π‐dimer pair reinforced with C—H_β…F(—C) interactions (abbreviated as C—H_β…F—C,C—H_β…F—C). The compounds [4,4′‐(CF₃CH₂OCH₂)₂‐2,2′‐bpy]M Cl₂ [M = Pd, ( 3 ), and M = Pt, ( 4 )] have been reported to be isomorphous [Lu et al. (2012). J. Fluorine Chem. 137 , 54–56], yet with disorder in the fluorous regions. The molecules of ( 3 ) [or ( 4 )] also form similar stacks, but with alternating π‐dimer pairs between the (α,β; α,β) and (β,β) forms. Through (C—)H…Cl hydrogen‐bond interactions, one molecule of ( 1 ) [or ( 2 )] is expanded into an aggregate of two inversion‐related π‐dimer pairs, one pair in the (α,α) form and the other pair in the (C—H_β…F—C,C—H_β…F—C) form, with the plane normals making an interplanar angle of 58.24 (3)°. Due to the demands of maintaining a high coordination number around the metal‐bound Cl atoms in molecule ( 1 ) [or ( 2 )], the ponytails of molecule ( 1 ) [or ( 2 )] bend outward; in contrast, the ponytails of molecule ( 3 ) [or ( 4 )] bend inward.     

Weak hydrogen bonding and fluorous interactions in the chloride and bromide salts of 4‐[(2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium

Neutralization of 4‐[(2,2,3,3‐tetrafluoropropoxy)methyl]pyridine with hydrohalo acids HX (X = Cl and Br) yielded the pyridinium salts 4‐[(2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium chloride, C₉H₁₀F₄NO⁺·Cl⁻, (1), and 4‐[(2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium bromide, C₉H₁₀F₄NO⁺·Br⁻, (2), both carrying a fluorous side chain at the para position of the pyridinium ring. Single‐crystal X‐ray diffraction techniques revealed that (1) and (2) are isomorphous. The halide anions accept four hydrogen bonds from N—H, ortho‐C—H and CF₂—H groups. Two cations and two anions form a centrosymmetric dimeric building block, utilizing complimentary N—H…X …H—Csp ³ connections. These dimers are further crosslinked, utilizing another complimentary Csp ²—H…X …H—Csp ² connection. The pyridinium rings are π‐stacked, forming columns running parallel to the a axis that make angles of ca 44–45° with the normal to the pyridinium plane. There are also supramolecular C—H…F—C interactions, namely bifurcated C—H…F and bifurcated C—F…H interactions; additionally, one type II C—F…F—C halogen bond has been observed.     

4,4′‐Bis(2,2,2‐trifluoroethoxymethyl)‐2,2′‐bipyridine

As part of a homologous series of novel polyfluorinated bipyridyl (bpy) ligands, the title compound, C₁₆H₁₄F₆N₂O₂, contains the smallest fluorinated group, viz. CF₃. The molecule resides on a crystallographic inversion centre at the mid‐point of the pyridine C_ipso—C_ipso bond. Therefore, the bpy skeleton lies in an anti conformation to avoid repulsion between the two pyridyl N atoms. Weak intramolecular C—H...N and C—H...O interactions are observed, similar to those in related polyfluorinated bpy–metal complexes. A π–π interaction is observed between the bpy rings of adjacent molecules and this is probably a primary driving force in crystallization. Weak intermolecular C—H...N hydrogen bonding is present between one of the CF₃CH₂– methylene H atoms and a pyridyl N atom related by translation along the [010] direction, in addition to weak benzyl‐type C—H...F interactions to atoms of the terminal CF₃ group. It is of note that the O—CH₂CF₃ bond is almost perpendicular to the bpy plane.     

The Evolution Aspect in the Crystallization Process of [5,5′‐(HCF2CF2CH2OCH2)2‐2,2′‐bpy]MX2 (M = Pt,Pd; X = I,Br): Role of the Intramolecular CF2─H…X(─M) Hydrogen Bonds

The general species (2,2′‐bpy)MX₂ (M = Pd, Pt; X = Br, I) in a crystallization process results in an isomorphous convergence in P2₁/c. Yet, with polyfluorinated side chains, the general [5,5′‐(HCF₂CF₂CH₂OCH₂)₂‐2,2′‐bpy]MX₂ species proceeds to crystallize the isomorphous structures of 5 (M = Pt; X = I) and 6 (M = Pd; X = I) in P2₁/c only; structure 7 (M = Pt; X = Br) crystallizes in P2₁/c but is not isomorphous with 5 and 6 , and structure 8 (M = Pd; X = Br) forms differently in P–1. The causes making the system nonlinear are (1) the intramolecular CF₂─H^…X(─M) hydrogen bonds found in 5–7 but not in 8, and (2) in response to the transition from I to Br, bifurcated [C─H^…]₂ F ─C hydrogen bonds that are formed in 5 and 6 and bifurcated C─ H [^…F─C]₂ hydrogen bonds in 7 . Additionally, the intramolecular CF₂─H^…X(─M) hydrogen bonding from compounds 5–7 could be affirmed by the IR studies.     

Weak hydrogen and halogen bonding in 4‐[(2,2‐difluoroethoxy)methyl]pyridinium iodide and 4‐[(3‐chloro‐2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium iodide

To enable a comparison between a C—H…X hydrogen bond and a halogen bond, the structures of two fluorous‐substituted pyridinium iodide salts have been determined. 4‐[(2,2‐Difluoroethoxy)methyl]pyridinium iodide, C₈H₁₀F₂NO⁺·I⁻, (1), has a –CH₂OCH₂CF₂H substituent at the para position of the pyridinium ring and 4‐[(3‐chloro‐2,2,3,3‐tetrafluoropropoxy)methyl]pyridinium iodide, C₉H₉ClF₄NO⁺·I⁻, (2), has a –CH₂OCH₂CF₂CF₂Cl substituent at the para position of the pyridinium ring. In salt (1), the iodide anion is involved in one N—H…I and three C—H…I hydrogen bonds, which, together with C—H…F hydrogen bonds, link the cations and anions into a three‐dimensional network. For salt (2), the iodide anion is involved in one N—H…I hydrogen bond, two C—H…I hydrogen bonds and one C—Cl…I halogen bond; additional C—H…F and C—F…F interactions link the cations and anions into a three‐dimensional arrangement.     

Secondary inter­actions in two related terphenyl derivatives: 2′,5′‐dimethyl‐p‐terphenyl and 2′,5′‐bis­(bromo­meth­yl)‐p‐terphen­yl

In 2′,5′‐dimethyl‐p‐terphenyl, C₂₀H₁₈, which displays pseudosymmetry (the true space group is Pna2₁, but less satisfactory refinement can also be achieved in Pbcn), the mol­ecules are linked into chains by two short C—H⋯π inter­actions to the centroid of the central ring. In 2′,5′‐bis­(bromo­meth­yl)‐p‐terphenyl, C₂₀H₁₆Br₂, the polar CH₂Br groups cause mol­ecules to aggregate via C—H⋯Br and Br⋯Br inter­actions, forming a layer structure, in which the phenyl rings project outwards from the central, more polar, region.     

A luminescent bis(pyridyl)‐substituted benzimidazole platinum(II) complex exhibiting an intermolecular anagostic interaction

The photophysical properties of transition metal complexes of the 5,6‐dimethyl‐2‐(pyridin‐2‐yl)‐1‐(pyridin‐2‐ylmethyl)‐1H‐benzimidazole ligand are of interest. Dichlorido[5,6‐dimethyl‐2‐(pyridin‐2‐yl)‐1‐(pyridin‐2‐ylmethyl)‐1H‐benzimidazole‐κ²N ²,N ³]platinum(II), [PtCl₂(C₂₀H₁₈N₄)], is luminescent in the solid state at room temperature. The compound displays a distorted square‐planar coordination geometry. The Pt—N(imidazole) bond length is shorter than the Pt—N(pyridine) bond length. The extended structure reveals that symmetry‐related molecules display weak C—H…N, C—H…Cl, and C—H…Pt hydrogen‐bonding interactions that are clearly discernable in the Hirshfeld surface and fingerprint plots. The intermolecular C—H…Pt and C—H…N interactions have been explored using density functional theory. The result of an analysis of the distance dependence of C—H…Pt yields a value consistent with that observed in the solid‐state structure. The energy of interaction for the C—H…Pt interaction is found to be about −11 kJ mol⁻¹.     

Di‐μ‐pivalamidato‐κ4N:O;O:N‐bis­[(2,2′‐bi­pyridine‐κ2N,N′)(sulfato‐κO)­platinum(III)] tetrahydrate in a head‐to‐tail isomerism

The title compound, [Pt₂^III(C₅H₁₀NO)₂(SO₄)₂(C₁₀H₈N₂)₂]·4H₂O, is the first reported example of a complex in which an amidate‐bridged Pt(bpy) dimer is stabilized in the oxidation level of Pt^III (bpy is 2,2′‐bi­pyridine). The asymmetric unit consists of one half of the formula unit with a twofold axis passing through the center of the dimer. The intradimer Pt^III—Pt^III bond distance [2.5664 (6) Å] is comparable to those reported for α‐pyridonate‐bridged cis‐diammineplatinum(III) dimers [2.5401 (5)–2.5468 (8) Å; Hollis & Lippard (1983). Inorg. Chem. 22 , 2605–2614], in spite of the close contact between the bpy planes within the dimeric unit. The axial Pt—O_sulfate distance is 2.144 (7) Å.     

Reaction‐path calculations and crystal structures of 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dichloride dihydrate and 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dibromide

The design of new organic–inorganic hybrid ionic materials is of interest for various applications, particularly in the areas of crystal engineering, supramolecular chemistry and materials science. The monohalogenated intermediates 1‐(2‐chloroethyl)pyridinium chloride, C₅H₅NCH₂CH₂Cl⁺·Cl⁻, (I′), and 1‐(2‐bromoethyl)pyridinium bromide, C₅H₅NCH₂CH₂Br⁺·Br⁻, (II′), and the ionic disubstituted products 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dichloride dihydrate, C₁₂H₁₄N₂²⁺·2Cl⁻·2H₂O, (I), and 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dibromide, C₁₂H₁₄N₂²⁺·2Br⁻, (II), have been isolated as powders from the reactions of pyridine with the appropriate 1,2‐dihaloethanes. The monohalogenated intermediates (I′) and (II′) were characterized by multinuclear NMR spectroscopy, while (I) and (II) were structurally characterized using powder X‐ray diffraction. Both (I) and (II) crystallize with half the empirical formula in the asymmetric unit in the triclinic space group P. The organic 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dications, which display approximate C2h symmetry in both structures, are situated on inversion centres. The components in (I) are linked via intermolecular O—H…Cl, C—H…Cl and C—H…O hydrogen bonds into a three‐dimensional framework, while for (II), they are connected via weak intermolecular C—H…Br hydrogen bonds into one‐dimensional chains in the [110] direction. The nucleophilic substitution reactions of 1,2‐dichloroethane and 1,2‐dibromoethane with pyridine have been investigated by ab initio quantum chemical calculations using the 6–31G** basis. In both cases, the reactions occur in two exothermic stages involving consecutive S_N2 nucleophilic substitutions. The isolation of the monosubstituted intermediate in each case is strong evidence that the second step is not fast relative to the first.     

Supramolecular architectures in cytosinium 6‐chloronicotinate monohydrate and 5‐bromo‐6‐methylisocytosinium hydrogen sulfate

Aminopyrimidine derivatives are biologically important as they are components of nucleic acids and drugs. The crystals of two new salts, namely cytosinium 6‐chloronicotinate monohydrate, C₄H₆N₃O⁺·C₆H₃ClNO₂⁻·H₂O, ( I ), and 5‐bromo‐6‐methylisocytosinium hydrogen sulfate (or 2‐amino‐5‐bromo‐4‐oxo‐6‐methylpyrimidinium hydrogen sulfate), C₅H₇BrN₃O⁺·HSO₄⁻, ( II ), have been prepared and characterized by single‐crystal X‐ray diffraction. The pyrimidine ring of both compounds is protonated at the imine N atom. In hydrated salt ( I ), the primary R₂²(8) ring motif (supramolecular heterosynthon) is formed via a pair of N—H…O(carboxylate) hydrogen bonds. The cations, anions and water molecule are hydrogen bonded through N—H…O, N—H…N, O—H…O and C—H…O hydrogen bonds, forming R₂²(8), R₃²(7) and R₅⁵(21) motifs, leading to a hydrogen‐bonded supramolecular sheet structure. The supramolecular double sheet structure is formed via water–carboxylate O—H…O hydrogen bonds and π–π interactions between the anions and the cations. In salt ( II ), the hydrogen sulfate ions are linked via O—H…O hydrogen bonds to generate zigzag chains. The aminopyrimidinium cations are embedded between these zigzag chains. Each hydrogen sulfate ion bridges two cations via pairs of N—H…O hydrogen bonds and vice versa, generating two R₂²(8) ring motifs (supramolecular heterosynthon). The cations also interact with one another via halogen–halogen (Br…Br) and halogen–oxygen (Br…O) interactions.     

Three‐dimensional framework structures: isomorphous bis(2,6‐diamino‐3,5‐dibromopyridinium) tetrabromidometallate(II) salts with CdII and MnII

In the structural motifs of two isomorphous triclinic salts, (C₅H₆Br₂N₃)₂[MBr₄] (M = Cd^II and Mn^II), each [MBr₄]²⁻ anion interacts with eight surrounding 2,6‐diamino‐3,5‐dibromopyridinium cations through intermolecular C/N—H...Br and Br...Br interactions, leading to a three‐dimensional framework structure. The cations show a minor degree of π–π stacking, adding extra stability to the three‐dimensional architecture.     

Supramolecular architectures in two 1:1 cocrystals of 5‐fluorouracil with 5‐bromothiophene‐2‐carboxylic acid and thiophene‐2‐carboxylic acid

In solid‐state engineering, cocrystallization is a strategy actively pursued for pharmaceuticals. Two 1:1 cocrystals of 5‐fluorouracil (5FU; systematic name: 5‐fluoro‐1,3‐dihydropyrimidine‐2,4‐dione), namely 5‐fluorouracil–5‐bromothiophene‐2‐carboxylic acid (1/1), C₅H₃BrO₂S·C₄H₃FN₂O₂, (I), and 5‐fluorouracil–thiophene‐2‐carboxylic acid (1/1), C₄H₃FN₂O₂·C₅H₄O₂S, (II), have been synthesized and characterized by single‐crystal X‐ray diffraction studies. In both cocrystals, carboxylic acid molecules are linked through an acid–acid R ₂²(8) homosynthon (O—H…O) to form a carboxylic acid dimer and 5FU molecules are connected through two types of base pairs [homosynthon, R ₂²(8) motif] via a pair of N—H…O hydrogen bonds. The crystal structures are further stabilized by C—H…O interactions in (II) and C—Br…O interactions in (I). In both crystal structures, π–π stacking and C—F…π interactions are also observed.     

Supramolecular interactions in a copper(II) 4′‐(4‐bromophenyl)‐2,2′:6′,2′′‐terpyridine complex

The title compound, [4′‐(4‐bromophenyl)‐2,2′:6′,2′′‐terpyridine]chlorido(trifluoromethanesulfonato)copper(II), [Cu(CF₃O₃S)Cl(C₂₁H₁₄BrN₃)], is a new copper complex containing a polypyridyl‐based ligand. The Cu^II centre is five‐coordinated in a square‐pyramidal manner by one substituted 2,2′:6′,2′′‐terpyridine ligand, one chloride ligand and a coordinated trifluoromethanesulfonate anion. The Cu—N bond lengths differ by 0.1 Å for the peripheral and central pyridine rings [2.032 (2) (mean) and 1.9345 (15) Å, respectively]. The presence of the trifluoromethanesulfonate anion coordinated to the metal centre allows Br...F halogen–halogen interactions, giving rise to the formation of a dimer about an inversion centre. This work also demonstrates that the rigidity of the ligand allows the formation of other types of nonclassical interactions (C—H...Cl and C—H...O), yielding a three‐dimensional network.     

Hydrogen bonding in the bromide salts of 4‐aminobenzoic acid and 4‐aminoacetophenone

In the title compounds, 4‐carboxyanilinium bromide, C₇H₈NO₂⁺·Br⁻, (I), and 4‐acetylanilinium bromide, C₈H₁₀NO⁺·Br⁻, (II), each asymmetric unit contains a discrete cation with a protonated amino group and a halide anion. Both crystal structures are characterized by two‐dimensional hydrogen‐bonded networks. The ions in (I) are connected via N—H...Br, N—H...O and O—H...Br hydrogen bonds, with three characteristic graph‐set motifs, viz. C(8), C₂¹(4) and R₃²(8). The centrosymmetric hydrogen‐bonded R²₂(8) dimer motif characteristic of carboxylic acids is absent. The ions in (II) are connected via N—H...Br and N—H...O hydrogen bonds, with two characteristic graph‐set motifs, viz. C(8) and R₄²(8). The significance of this study lies in its illustration of the differences between the supramolecular aggregations in two similar compounds. The presence of the methyl group in (II) at the site corresponding to the hydroxyl group in (I) results in a significantly different hydrogen‐bonding arrangement.     

Halogen bonding in 1,2‐dibromo‐4,5‐dimethoxybenzene and 1,2‐diiodo‐4,5‐dimethoxybenzene

An interesting case of `halogen‐bonding‐promoted' crystal structure architecture is presented. The two title compounds, C₈H₈Br₂O₂ and C₈H₈I₂O₂, have almost indistinguishable molecular structures but very different spatial organization, and this is mainly due to differences in the halogen‐bonding interactions in which the different species present, i.e. Br and I, take part. The dibromo structure exhibits a π‐bonded columnar array involving all four independent molecules in the asymmetric unit, with intercolumnar interactions governed by C—Br...Br—C links and with no C—Br...O/N interactions present. In the diiodo structure, instead, the C—I...O synthon prevails, defining linear chains, in turn interlinked by C—I...I—C interactions.     

Unconventional hydrogen bonding and π‐stacking in two substituted pyridine carboxamides

The crystal structures of two para‐substituted aryl derivatives of pyridine‐2‐carboxamide, namely N‐(4‐fluorophenyl)pyridine‐2‐carboxamide, C₁₂H₉FN₂O, (I), and N‐(4‐nitrophenyl)pyridine‐2‐carboxamide, C₁₂H₉N₃O₃, (II), have been studied. Compound (I) exhibits unconventional aryl–carbonyl C—H...O and pyridine–fluorine C—H...F hydrogen bonding in two dimensions and well defined π‐stacking involving pyridine rings in the third dimension. The conformation of (II) is more nearly planar than that of (I) and the intermolecular interactions comprise one‐dimensional aryl–carbonyl C—H...O hydrogen bonds leading to a stepped or staircase‐like progression of loosely π‐stacked molecules. The close‐packed layers of planar π‐stacked molecules are related by inversion symmetry. Two alternating interplanar separations of 3.439 (1) and 3.476 (1) Å are observed in the crystal lattice and are consistent with a repetitive packing sequence, ABA′B′AB…, for the π‐stacked inversion pairs of (II).     

Pt2II and Pt2III dimers containing a Pt2(2,2′‐bipyridine)2(μ‐N,N‐dimethyl­guanidinato)2 unit

The syntheses and crystal structures of the title Pt₂^II and Pt₂^III dimers doubly bridged with N,N‐dimethyl­guanidinate ligands, namely bis­(μ‐N,N‐dimethyl­guanidinato)bis­[(2,2′‐bipyridine)platinum(II)](Pt—Pt) bis­(hexa­fluoro­phosphate) acetonitrile disolvate, [Pt₂^II(C₃H₈N₃)₂(C₁₀H₈N₂)₂](PF₆)₂·2CH₃CN, (I), and guanidinium bis­(μ‐N,N‐dimethyl­guanidinato)bis­[(2,2′‐bipyridine)sulfatoplatinum(III)](Pt—Pt) bis­(hexa­fluoro­phosphate) nitrate hexa­hydrate, (C₃H₁₀N₃)[Pt^III₂(C₃H₈N₃)₂(SO₄)₂(C₁₀H₈N₂)₂]NO₃·6H₂O, (II), are reported. The oxidation of the Pt₂^II dimer into the Pt₂^III dimer results in a marked shortening of the Pt—Pt distance from 2.8512 (6) to 2.5656 (4) Å. The change is mainly compensated for by the change in the dihedral angle between the two Pt coordination planes upon oxidation, from 21.9 (2) to 16.9 (3)°. We attribute the relatively strong one‐dimensional stack of dimers achieved in the Pt₂^II compound in part to the strong Pt^II⋯C(bpy) associations (bpy is 2,2′‐bipyridine) in the crystal structure [Pt⋯C = 3.416 (10) and 3.361 (12) Å].     

Three polymorphs of 3‐(3‐phenyl‐1H‐1,2,4‐triazol‐5‐yl)‐2H‐1‐benzopyran‐2‐one formed from different solvents

The polymorphic study of 3‐(3‐phenyl‐1H‐1,2,4‐triazol‐5‐yl)‐2H‐1‐benzopyran‐2‐one, C₁₇H₁₁N₃O₂, was performed due to its potential biological activity and revealed three polymorphic modifications in the triclinic space group P, the monoclinic space group P2₁ and the orthorhombic space group Pbca. These polymorphs have a one‐column layered type of crystal organization. The strongest interactions between the molecules of the studied structures is stacking between π‐systems, while N—H…N and C—H…O hydrogen bonds link stacked columns forming layers as a secondary basic structural motif. C—H…π hydrogen bonds were observed between neighbouring layers and their role is the least significant in the formation of the crystal structure. Packing differences between the polymorphic modifications are minor and can be identified only using an analysis based on a comparison of the pairwise interaction energies.     

HBr or not HBr? That is the question: crystal structure of 6‐hydroxy‐1,4‐diazepane‐1,4‐diium dibromide redetermined

Liu et al. [Chin. J. Struct. Chem. (1996). 15 , 371–373] reported the structure of 6‐hydroxy‐1,4‐diazepane di(hydrogen bromide), C₅H₁₂N₂O·2HBr, which was interpreted in terms of neutral diazepane and HBr molecules. We found, however, ample evidence that the formation of an organic salt, consisting of a diammonium cation and two bromide anions, is more plausible. This interpretation is also in agreement with thermogravimetric analysis and with the observed solution behaviour. The crystal structure of 6‐hydroxy‐1,4‐diazepane‐1,4‐diium dibromide, C₅H₁₄N₂O²⁺·2Br^?, measured at 142 K, crystallized in the orthorhombic space group P2₁2₁2₁. The structure displays O—H…Br and N—H…Br hydrogen bonding. Contact distances are given. A search in the Cambridge Structural Database for the singly‐bonded H—Br moiety revealed a total of 69 structures. The question, whether these structures really include HBr as neutral molecules or rather Br^? anions and a protonated substrate such as an amine, is addressed.     

Two‐Dimensional Monovalent Copper Halide Coordination Polymers Incorporating Anti‐Conformation 3,3′‐Bipyridine

Hydrothermal treatment of aqueous mixtures of copper(II) halides and 3,3′‐bipyridine (3,3′‐bpy) has afforded the coordination polymers [CuCl(3,3′‐bpy)]_n ( 1 ) and [Cu₂Br₂(3,3′‐bpy)]_n ( 2 ), which were analyzed via single crystal X‐ray diffraction, infrared spectroscopy, and elemental analysis. The structure of 1 consists of two‐dimensional (2‐D) layers constructed from the linkage of castellated one‐dimensional (1‐D) [CuCl]_n stepped chains through anti‐conformation 3,3′‐bpy tethers. Compound 2 presents a related 2‐D sheet motif, albeit built from infinite 1‐D [Cu₂Br₂]_n ladders strutted by 3,3′‐bpy ligands in anti conformation. In both cases neighboring 2‐D sheets stack into 3‐D via weak C–H···halogen interactions.