Studies on Properties of Tetra‐p‐nitro‐tetra‐O‐alkylcalix[4]arenes

Ibis paper reports the properties of the novel tetra‐p‐nitro‐tetra‐O‐alkyl‐calix[4]arenes (alkyl= n‐C₄H₉, 1; n‐C₈H₁₇ 2; n‐C₁₂H₂₅, 3; n‐C₁₆H₃₃, 4). X‐ray crystallographic analysis and ¹H NMR revealed that they exist as pinched‐cone conformation in crystal or cone conformation in solution. EFISH experiments at 1064 nm in CHCl₃, indicated that tetra‐p‐nitro‐tetra‐O‐butyl‐calix[4]arene (1) has higher hyperpolarizability β, values than the corresponding reference compound p‐nitro‐phenyl butyl ether, without red shift of the charge transfer band. Compounds 2, 3 and 4 with longer alkyl chains can form monolayer at the air/water.     

Additional insights from very‐high‐resolution 13C NMR spectra of long‐chain n‐alkanes

New information has been obtained from very‐high‐resolution ¹³C NMR studies of a series of long‐chain n‐alkanes. These compounds are fundamentally important in the petroleum industry and are essential to the life of some plants, flowers, and insects. At least partial resolution of the ten different ¹³C NMR signals of n‐C₂₀H₄₂ is observed at 11.7 T for solutions in C₆D₆ or C₆D₅CD₃. A ¹³C T₁ inversion‐recovery experiment provides much more detailed information than in previous studies of long‐chain n‐alkanes, demonstrates a steady increase in the relaxation times of the ten different carbons proceeding from the middle to the end of the chain because of segmental motion, and thus confirms the assignments for the interior carbons. In contrast, there is significant overlap for the signals for C‐7 and the more interior carbons in a solution of n‐C₁₆ or longer chain alkanes in CDCl₃. Not only are the chemical shifts sensitive to the solvent used, but also the relative chemical shifts change. Signals for the interior carbons of the odd‐number alkanes in CDCl₃ are better resolved than in the spectra of their even‐number counterparts. Some mixed aromatic solvent systems give increased dispersion of the cluster of C‐6 through C‐10 signals of n‐C₂₀H₄₂, n‐C₂₁H₄₄, and n‐C₂₂H₄₆. However, none of the solvents used could even partially resolve the C‐10 and C‐11 signals of n‐C₂₁H₄₄ or n‐C₂₂H₄₆ at 11.7 T, which may result from a different distribution of conformers for n‐C₂₁H₄₄ or n‐C₂₂H₄₆ than for n‐C₂₀H₄₂ and shorter n‐alkanes. Copyright © 2013 John Wiley & Sons, Ltd.     

Efficient Separation of n‐Butene and iso‐Butene by Flexible Ultramicroporous Metal‐Organic Frameworks with Pocket‐like Cavities

Efficient separation of n‐butene (n‐C₄H₈) and iso‐butene (iso‐C₄H₈) is of significance for the upgrading of C4 olefins to high‐value end products but remains one of the major challenges in hydrocarbon purifications owing to their similar structures. Herein, we report a flexible metal‐organic framework, MnINA (INA=isonicotinate), featuring one‐dimensional pore channels with periodically large pocket‐like cavities connected by narrow bottlenecks, for the first time for efficient n‐/iso‐C₄H₈ separation. MnINA with smaller pore size (4.62 Å) compared with CuINA (4.84 Å), exhibits steep adsorption isotherms and high capacity of 1.79 mmol g^?1 for n‐C₄H₈ (4.46 Å) through strong host‐guest interactions via C?H???π bonding. The narrow bottlenecks exert barriers for the large molecules of iso‐C₄H₈ (4.84 Å) within the gate‐opening pressure range of 0–0.1 bar. This gives rise to MnINA with excellent separation selectivity of 327.7 for n‐/iso‐C₄H₈ mixture. The adsorption mechanism for n‐C₄H₈ and the gate‐opening effect were investigated by dispersion‐corrected density functional (DFT‐D) theory, verifying the strong interactions between n‐C₄H₈ and the frameworks as well as the gate‐opening effect derived from the rotation of organic linkers. The breakthrough tests confirmed MnINA and CuINA can be promising candidates for n‐/iso‐C₄H₈ separation.     

Synthesis and Characterization of New 3‐(3‐Hydroxyphenyl)‐4‐ alkyl‐3,4‐dihydrobenzo[e][1,3]oxazepine‐1,5‐dione Compounds

A series of 3‐(3‐hydroxyphenyl)‐4‐alkyl‐3,4‐dihydrobenzo[e][1,3]oxazepine‐1,5‐dione compounds with general formula C_nH_2n+1CNO(CO)₂C₆H₄(C₆H₄OH) in which n are even parity numbers from 2 to 18. The structure determinations on these compounds were performed by FT‐IR spectroscopy which indicated that the terminal alkyl chain attached to the oxazepine ring was fully extended. Conformational analysis in DMSO at ambient temperature was carried out for the first time via high resolution ¹H NMR and ¹³C NMR spectroscopy.     

catena‐Poly[[(tetrahydrofuran‐κO)potassium]‐μ‐(η5:η5)‐2,3,4,5‐tetramethyl‐1‐n‐pentylcyclopentadienyl]

The title compound, [K(C₁₄H₂₃)(C₄H₈O)]_n, comprises zigzag chains of alternating bridging 2,3,4,5‐tetramethyl‐1‐n‐pentylcyclopentadienyl ligands and potassium ions, with an ancillary tetrahydrofuran ligand in the coordination environment of potassium. The coordination polymer strands so formed extend by 2₁ screw symmetry in the b‐axis direction. The chemically modified cyclopentadienyl ligand, with a tethered n‐pentyl group, was synthesized from 2,3,4,5‐tetramethylcyclopent‐2‐enone by a Grignard reaction.     

Undecacarbonyl(methylcyclopentadienyl)‐tetrahedro‐triiridiummolybdenum,undecacarbonyl(tetramethylcyclopentadienyl)‐tetrahedro‐triiridiummolybdenum and undecacarbonyl(pentamethylcyclopentadienyl)‐tetrahedro‐triiridiummolybdenum

The three title compounds tri‐μ‐carbonyl‐1:2κ²C;1:3κ²C;2:3κ²C‐octacarbonyl‐1κC,2κ²C,3κ²C,4κ³C‐η⁵‐methylcyclopentadienyl‐tetrahedro‐triiridiummolybdenum(3 Ir—Ir)(3 Ir—Mo), tri‐μ‐carbonyl‐1:2κ²C;1:3κ²C;2:3κ²C‐octacarbonyl‐1κC,2κ²C,3κ²C,4κ³C‐η⁵‐tetramethylcyclopentadienyl‐tetrahedro‐triiridiummolybdenum(3 Ir—Ir)(3 Ir—Mo) and tri‐μ‐carbonyl‐1:2κ²C;1:3κ²C;2:3κ²C‐octacarbonyl‐1κC,2κ²C,3κ²C,4κ³C‐η⁵‐pentamethylcyclopentadienyl‐tetrahedro‐triiridiummolybdenum(3 Ir—Ir)(3 Ir—Mo), [MoIr₃(η⁵‐C₅H_5?nMe_n)(μ‐CO)₃(CO)₈], where n = 1, 4 or 5, have a pseudo­tetrahedral MoIr₃ core geometry, with a η⁵‐C₅H_5?nMe_n group ligating the Mo atom, bridging carbonyls spanning the edges of an MoIr₂ face, and eight terminally bound carbonyls.     

Single‐Step Gas‐Phase Polyperfluoroalkylation of Naphthalene Leads to Thermodynamic Products

High‐temperature gas‐phase, solvent‐ and catalyst‐free reaction of naphthalene with an excess of R_FI reagent (R_F?CF₃, C₂F₅, n‐C₃F₇, and n‐C₄F₉) was used for the first time to produce a series of highly perfluoroalkylated naphthalene products NAPH(R_F)_n with n=2–5. Four 95+ % pure 1,3,5,7‐NAPH(R_F)₄ with R_F?CF₃, C₂F₅, n‐C₃F₇, and n‐C₄F₉ were isolated using a simple chromatography‐free procedure. These new compounds were fully characterized by ¹⁹F and ¹H NMR spectroscopy, X‐ray crystallography (for R_F?CF₃ and C₂F₅), atmospheric‐pressure chemical ionization mass spectrometry, and cyclic and square‐wave voltammetry. DFT calculations confirm that the proposed synthesis yields the most stable isomers that have not been accessed by alternative preparation techniques.     

Synthesis and Self‐Assembly of NCN‐Pincer Pd‐Complex‐Bound Norvalines

The NCN‐pincer Pd‐complex‐bound norvalines Boc‐D /L ‐[PdCl(dpb)]Nva‐OMe ( 1 ) were synthesized in multigram quantities. The molecular structure and absolute configuration of 1 were unequivocally determined by single‐crystal X‐ray structure analysis. The robustness of 1 under acidic/basic conditions provides a wide range of N‐/C‐terminus convertibility based on the related synthetic transformations. Installation of a variety of functional groups into the N‐/C‐terminus of 1 was readily carried out through N‐Boc‐ or C‐methyl ester deprotection and subsequent condensations with carboxylic acids, R¹COOH, or amines, R²NH₂, to give the corresponding N‐/C‐functionalized norvalines R¹‐D /L ‐[PdCl(dpb)]Nva‐R² 2 – 9 . The dipeptide bearing two Pd units 10 was successfully synthesized through the condensation of C‐free 1 with N‐free 1 . The robustness of these Pd‐bound norvalines was adequately demonstrated by the preservation of the optical purity and Pd unit during the synthetic transformations. The lipophilic Pd‐bound norvalines L ‐ 2 , Boc‐L ‐[PdCl(dpb)]Nva‐NH‐n‐C₁₁H₂₃, and L ‐ 4 , n‐C₄H₉CO‐L ‐[PdCl(dpb)]Nva‐NH‐n‐C₁₁H₂₃, self‐assembled in aromatic solvents to afford supramolecular gels. The assembled structures in a thermodynamically stable single crystal of L ‐ 2 and kinetically stable supramolecular aggregates of L ‐ 2 were precisely elucidated by cryo‐TEM, WAX, SAXS, UV/Vis, IR analyses, and single‐crystal X‐ray crystallography. An antiparallel β‐sheet‐type aggregate consisting of an infinite one‐dimensional hydrogen‐bonding network of amide groups and π‐stacking of PdCl(dpb) moieties was observed in the supramolecular gel fiber of L ‐ 2 , even though discrete dimers are assembled through hydrogen bonding in the thermodynamically stable single crystal of L ‐ 2 . The disparate DSC profiles of the single crystal and xerogel of L ‐ 2 indicate different thermodynamics of the molecular assembly process.     

On the Dynamic Interaction of n‐Butane with Imidazolium‐Based Ionic Liquids

The impact of a reactant from the gas phase on the surface of a liquid and its transfer through this gas/liquid interface are crucial for various concepts applying ionic liquids (ILs) in catalysis. We investigated the first step of the adsorption dynamics of n‐butane on a series of 1‐alkyl‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide ILs ([C_nC₁Im][Tf₂N]; n=1, 2, 3, 8). Using a supersonic molecular beam in ultra‐high vacuum, the trapping of n‐butane on the frozen ILs was determined as a function of surface temperature, between 90 and 125 K. On the C₈‐ and C₃‐ILs, n‐butane adsorbs at 90 K with an initial trapping probability of ≈0.89. The adsorption energy increases with increasing length of the IL alkyl chain, whereas the ionic headgroups seem to interact only weakly with n‐butane. The absence of adsorption on the C₁‐ and C₂‐ILs is attributed to a too short residence time on the IL surface to form nuclei for condensation even at 90 K.     

A novel heterocyclic compound: catena‐poly[[[diaquasodium(I)]‐di‐μ‐aqua] hemi(1,5‐dihydroxy‐4,8,9‐trioxa‐2,6‐diazabicyclo[3.3.1]nona‐2,6‐diene‐3,7‐diolate)]

In the title compound, {[Na(H₂O)₄]₂(C₄H₂N₂O₇)}_n, the 1,5‐dihydroxy‐4,8,9‐trioxa‐2,6‐diazabicyclo[3.3.1]nona‐2,6‐diene‐3,7‐diolate anion lies across a twofold axis in the space group C2/c; there are two independent Na sites, one on a twofold axis and the other on a centre of inversion. Hydrogen bonds link the {[Na(H₂O)₄]⁺}_n chains and diolate anions into a three‐dimensional framework.     

Two enamines derived from 1‐n‐alkyl‐3‐methylpyrazol‐5‐ones

The first two crystal structures of en­amines derived from 1‐n‐alkyl‐3‐methyl‐5‐pyrazolones, namely 1‐(n‐hexyl)‐3‐methyl‐4‐[1‐(phenyl­amino)­propyl­idene]‐2‐pyrazolin‐5‐one, C₁₉H₂₇N₃O, (I), and N,N′‐bis{1‐[1‐(n‐hexyl)‐3‐methyl‐5‐oxo‐2‐pyrazolin‐4‐yl­idene]­ethyl}hexane‐1,6‐di­amine, C₃₀H₅₂N₆O₂, (II), are reported. The mol­ecule of (II) lies about an inversion centre. Both (I) and (II) are stabilized by intramolecular N—H⋯O hydrogen bonding. This confirms previous results based on spectroscopic evidence alone.     

Structural investigation of one‐ and two‐dimensional coordination polymers based on cobalt–bis(dioxolene) units and 1‐hydroxy‐1,2,4,5‐tetrakis(pyridin‐4‐yl)cyclohexane

The combination of cobalt, 3,5‐di‐tert‐butyldioxolene (3,5‐dbdiox) and 1‐hydroxy‐1,2,4,5‐tetrakis(pyridin‐4‐yl)cyclohexane (tpch) yields two coordination polymers with different connectivities, i.e. a one‐dimensional zigzag chain and a two‐dimensional sheet. Poly[[bis(3,5‐di‐tert‐butylbenzene‐1,2‐diolato)bis(1,5‐di‐tert‐butyl‐4‐oxocyclohexa‐2,5‐dien‐1‐yl‐3‐olato)[μ₄‐1‐hydroxy‐1,2,4,5‐tetrakis(pyridin‐4‐yl)cyclohexane]cobalt(III)]–ethanol–water 1/7/5], {[Co₂(C₁₄H₂₀O₂)₄(C₂₆H₂₄N₄O)]·7C₂H₅OH·5H₂O}_n or {[Co₂(3,5‐dbdiox)₄(tpch)}·7EtOH·5H₂O}_n, is the second structurally characterized example of a two‐dimensional coordination polymer based on linked {Co(3,5‐dbdiox)₂} units. Variable‐temperature single‐crystal X‐ray diffraction studies suggest that catena‐poly[[[(3,5‐di‐tert‐butylbenzene‐1,2‐diolato)(1,5‐di‐tert‐butyl‐4‐oxocyclohexa‐2,5‐dien‐1‐yl‐3‐olato)cobalt(III)]‐μ‐1‐hydroxy‐1,2,4,5‐tetrakis(pyridin‐4‐yl)cyclohexane]–ethanol–water (1/1/5)], {[Co(C₁₄H₂₀O₂)₂(C₂₆H₂₄N₄O)]·C₂H₅OH·5H₂O}_n or {[Co(3,5‐dbdiox)₂(tpch)]·EtOH·5H₂O}_n, undergoes a temperature‐induced valence tautomeric interconversion.     

High‐Potential Perfluorinated Phthalocyanine–Fullerene Dyads for Generation of High‐Energy Charge‐Separated States: Formation and Photoinduced Electron‐Transfer Studies

High oxidation potential perfluorinated zinc phthalocyanines (ZnF_nPcs) are synthesised and their spectroscopic, redox, and light‐induced electron‐transfer properties investigated systematically by forming donor–acceptor dyads through metal–ligand axial coordination of fullerene (C₆₀) derivatives. Absorption and fluorescence spectral studies reveal efficient binding of the pyridine‐ (Py) and phenylimidazole‐functionalised fullerene (C₆₀Im) derivatives to the zinc centre of the F_nPcs. The determined binding constants, K, in o‐dichlorobenzene for the 1:1 complexes are in the order of 10⁴ to 10⁵ M ^?1; nearly an order of magnitude higher than that observed for the dyad formed from zinc phthalocyanine (ZnPc) lacking fluorine substituents. The geometry and electronic structure of the dyads are determined by using the B3LYP/6‐31G* method. The HOMO and LUMO levels are located on the Pc and C₆₀ entities, respectively; this suggests the formation of ZnF_nPc^.+–C₆₀Im^.? and ZnF_nPc^.+–C₆₀Py^.? (n=0, 8 or 16) intra‐supramolecular charge‐separated states during electron transfer. Electrochemical studies on the ZnPc–C₆₀ dyads enable accurate determination of their oxidation and reduction potentials and the energy of the charge‐separated states. The energy of the charge‐separated state for dyads composed of ZnF_nPc is higher than that of normal ZnPc–C₆₀ dyads and reveals their significance in harvesting higher amounts of light energy. Evidence for charge separation in the dyads is secured from femtosecond transient absorption studies in nonpolar toluene. Kinetic evaluation of the cation and anion radical ion peaks reveals ultrafast charge separation and charge recombination in dyads composed of perfluorinated phthalocyanine and fullerene; this implies their significance in solar‐energy harvesting and optoelectronic device building applications.     

1‐Octanol/Water Partition Coefficients of 1Alkyl‐3‐methylimidazolium Chloride

The solubilities of 1alkyl‐3‐methylimidazolium chloride, [C_nmim][Cl], where n=4, 8, 10, and 12, in 1octanol and water have been measured by a dynamic method in the temperature range from 270 to 370 K. The solubility data was used to calculate the 1octanol/water partition coefficients as a function of temperature and alkyl substituent. The melting point, enthalpies of fusion, and enthalpies of solid–solid phase transitions were determined by differential scanning calorimetry, DSC. The solubility of [C_nmim][Cl], where n=10 or 12 in 1octanol is comparable and higher than that of [C₄mim][Cl] in 1octanol. Liquid 1n‐octyl‐3‐methylimidazolium chloride, [C₈mim][Cl], is not miscible with 1octanol and water, consequently, the liquid–liquid equilibrium, LLE was measured in this system. The differences between the solubilities in water for n=4 and 12 are shown only in α₁ and γ₁ solid crystalline phases. Additionally, the immiscibility region was observed for the higher concentration of [C₁₀mim][Cl] in water. The intermolecular solute–solvent interaction of 1butyl‐3‐methylimidazolium chloride with water is higher than for other 1alkyl‐3‐methylimidazolium chlorides. The data was correlated by means of the UNIQUAC ASM and two modified NRTL equations utilizing parameters derived from the solid–liquid equilibrium, SLE. The root‐mean‐square deviations of the solubility temperatures for all calculated data are from 1.8 to 7 K and depend on the particular equation used. In the calculations, the existence of two solid–solid first‐order phase transitions in [C₁₂mim][Cl] has also been taken into consideration. Experimental partition coefficients (log P) are negative at three temperatures; this is evidence for the possible use of these ionic liquids as green solvents.     

Well‐Defined Amphiphilic C60‐PEG Conjugates: Water‐Soluble and Thermoresponsive Materials

For the preparation of well‐defined H₂O‐soluble C₆₀ polymers, several C₆₀‐PEG conjugates were prepared from a C₆₀ biscarboxylic acid derivative and monodisperse NH₂‐PEGs (NH₂‐EG_n, n = 4 – 36) via amide conjugation. When the relatively long PEGs (EG_n, n ≥ 12) were employed, the C₆₀‐PEG conjugates became completely H₂O‐soluble by forming micelle‐like structure shown by the data of surface tension, DLS, and cryo‐TEM. Interestingly, these H₂O‐soluble C₆₀‐PEG conjugates (C₆₀(EG_n)₂, n = 12 – 36) showed reversible thermoresponse to form larger aggregates (ca. 1 μm by DLS) at higher temperatures. The temperature for the aggregation was related to the lengths of PEGs attached to C₆₀; 29 °C (C₆₀(EG_n)₂, n = 12), 51 °C (n = 20), and 72 °C (n = 36). This thermoresponse was speculated to occur by dehydration of well‐organized PEG chains in the micelle‐type structure of monodisperse C₆₀‐PEG caused by gauche‐to‐anti conformational change of PEG anchors. This thermoresponse of well‐defined amphiphilic C₆₀‐PEG conjugates indicates potential applications in areas such as temperature sensors and thermoresponsive materials.     

Poly[(μ3‐benzene‐1,4‐diacetato)[μ2‐1,4‐bis(1,2,4‐triazol‐1‐yl)butane]cadmium(II)]: self assembly into a three‐dimensional supramolecular framework based on [Cd(μ3‐benzene‐1,4‐diacetate)] double chains

The title compound, [Cd(C₁₀H₈O₄)(C₈H₁₂N₆)]_n, crystallizes with an asymmetric unit comprising a divalent Cd^II atom, a benzene‐1,4‐diacetate (PBEA²⁻) ligand and a complete 1,4‐bis(1,2,4‐triazol‐1‐yl)butane (BTB) ligand. [Cd(PBEA)]_n double chains, arranged parallel to the c axis, are formed through an exo‐tridentate binding mode of the PBEA²⁻ ligands. These [Cd(PBEA)]_n double chains are pillared by tethering BTB ligands, in which the BTB shows a trans–trans–trans conformation, to establish [Cd(PBEA)(BTB)]_n two‐dimensional coordination polymer (4,4)‐layer slab patterns. The three‐dimensional supramolecular architecture is formed by C—H...O hydrogen bonds and C—H...π interactions.     

Carbo‐biphenyls and Carbo‐terphenyls: Oligo(phenylene ethynylene) Ring Carbo‐mers

Ring carbo‐mers of oligo(phenylene ethynylene)s (OPEn, n=0–2), made of C₂‐catenated C₁₈ carbo‐benzene rings, have been synthesized and characterized by NMR and UV‐vis spectroscopy, crystallography and voltammetry. Analyses of crystal and DFT‐optimized structures show that the C₁₈ rings preserve their individual aromatic character according to structural and magnetic criteria (NICS indices). Carbo‐terphenyls (n=2) are reversibly reduced at ca. ?0.42 V/SCE, i.e. 0.41 V more readily than the corresponding carbo‐benzene (?0.83 V/SCE), thus revealing efficient inter‐ring π‐conjugation. An accurate linear fit of E_1/2^red1 vs. the DFT LUMO energy suggests a notably higher value (?0.30 V/SCE) for a carbo‐quaterphenyl congener (n=3). Increase with n of the effective π‐conjugation is also evidenced by a red shift of two of the three main visible light absorption bands, all being assigned to TDDFT‐calculated excited states, one of them restricting to a HOMO→LUMO main one‐electron transition.     

Self‐Assembly of Imidazolium‐Based Surfactants in Magnetic Room‐Temperature Ionic Liquids: Binary Mixtures

The phase behaviour of binary mixtures of ionic surfactants (1‐alkyl‐3‐imidazolium chloride, C_nmimCl with n=14, 16 and 18) and imidazolium‐based ionic liquids (1‐alkyl‐3‐methylimidazolium tetrachloroferrate, C_nmimFeCl₄, with n=2 and 4) over a broad temperature range and the complete range of compositions is described. By using many complementary methods including differential scanning calorimetry (DSC), polarised microscopy, small‐angle neutron and X‐ray scattering (SANS/SAXS), and surface tension, the ability of this model system to support self‐assembly is described quantitatively and this behaviour is compared with common water systems. The existence of micelles swollen by the solvent can be deduced from SANS experiments and represent a possible model for aggregates, which has barely been considered for ionic‐liquid systems until now, and can be ascribed to the rather low solvophobicity of the surfactants. Our investigation shows that, in general, C_nmimCl is a rather weak amphiphile in these ionic liquids. The amphiphilic strength increases systematically with the length of the alkyl chain, as seen from the phase behaviour, the critical micelle concentration, and also the level of definition of the aggregates formed.     

[Hg8(μ‐n‐C3H7Te)12(μ‐Br)Br3] — Synthesis and Structure

The novel mercury‐tellurium cluster [Hg₈(μ‐n‐C₃H₇Te)₁₂(μ₂‐Br)Br₃] is formed during the reaction of HgBr₂ and (n‐C₃H₇Te)₂Hg in DMSO. Its crystal structure has been elucidated showing [Hg₈(μ‐n‐C₃H₇Te)₁₂(μ₂‐Br)]³⁺ units with a bromine‐centered distorted Hg₈ cube. The mercury atoms are bridged by n‐C₃H₇Te^— ligands and the resulting clusters are linked to a three‐dimensional network by bromine atoms. The close packing of the cluster is mainly determined by the flexible n‐propyl residues of the telluride building blocks.     

Polymorphism of 2,5‐[(diphenylphosphanyl)methyl]‐1,1,2,4,4,5‐hexaphenyl‐1,4‐diphospha‐2,5‐diboracyclohexane

2,5‐[(Diphenylphosphanyl)methyl]‐1,1,2,4,4,5‐hexaphenyl‐1,4‐diphospha‐2,5‐diboracyclohexane shows polymorphism as two tetrahydrofuran (THF) disolvates [C₆₄H₅₈B₂P₄·2C₄H₈O, (Ia) and (Ib)] and pseudo‐polymorphism as its toluene monosolvate [C₆₄H₅₈B₂P₄·C₇H₈, (Ic)]. In each of polymorphs (Ia) and (Ib), the diphosphadiboracyclohexane molecule is located on a centre of inversion. The THF molecule of (Ib) is disordered over two sites, with a site‐occupation factor of 0.612 (8) for the major‐occupied site. Both structures crystallize in the same space group (P2₁/n), but they display a different crystal packing. For pseudo‐polymorph (Ic), although the space group is P2₁/c, which is just a different setting of the P2₁/n space group of (Ia) and (Ib), the crystal packing is completely different. Although the crystal packing in these three structures is significantly different, their molecular conformations are surprisingly the same.