Olga Gallardo

Clathrate design for dioxane inclusion involving singly bridged triarylmethanol hosts. Synthesis, X-ray crystal structures and thermal stabilities of five inclusion compounds

A series of singly bridged triarylmethanols, with different substituents and modified bridging units, form crystalline inclusion compounds with dioxane. X-ray diffraction studies revealed hydrogen bonds between host and guest in all these structures, and in one case also a host-to-host hydrogen bond. Most crystals contain either 1 : 1 or 2 : 1 hydrogen-bonded host–dioxane complexes, dependent on the structural parameters of the host molecule. With both host–guest and host–host hydrogen bonds present, 4 : 1, host–dioxane units are formed. Some structures accommodate additional dioxane guests which are held by van der Waals forces. The stabilities of the different dioxane clathrates were studied by thermal analysis.

Roof-shaped hydroxy hosts: synthesis, complex formation and X-ray crystal structures of inclusion compounds with EtOH, nitroethane and benzene

A series of crystalline host molecules 1 and 2a–e, based on a characteristic 9,10-dihydro-9,10-ethanoanthracene rigid framework and appended diarylmethanol clathratogenic groups, has been synthesized and studied with regard to their inclusion behaviour. These hosts form crystalline inclusion compounds with a variety of uncharged organic molecules, ranging from protic dipolar to apolar compounds (183 different species), but show a preference for amines and aromatic hydrocarbons. The bis-methanols are largely superior to the mono-methanols, except for the 4-chlorophenyl substituted methanol, which has proved to have equal efficiency.The building principles and the mode of complexation of the host compound 2a(trans-α,α,α′,α′-tetraphenyl-9,10-dihydro-9,10-ethanoanthracene-11,12-dimethanol) with ethanol (protic), nitroethane (aprotic polar) and benzene (aprotic apolar) as guests have been investigated by single crystal X-ray diffraction. The conformation of the host molecule observed in the 1 : 2 (host: guest) EtOH complex is different from that in the nitroethane (1 : 1) or benzene (2 : 1) inclusions. The host–guest contact pattern in 2a·EtOH (1 : 2) features a huge 16-membered loop of H-bonds involving four functional OH groups of both host and guest, with one intra-host H-bond for each of the two host molecules of the 2 : 4 (host:guest) aggregate. On the other hand, in the compounds of 2a with the aprotic guest species nitroethane and benzene the host hydroxys are involved in specific intramolecular OH ⋯π-aryl contact, thus yielding true lattice-type inclusions, although with different organizations. Accordingly, in 2a·nitroethane (1 : 1) the polar guest units fill up the voids between the bulky host molecules, while in 2a·benzene (2 : 1) the host molecules are arranged so as to form tunnels in the crystallographic c direction, where the guests are located.

Crystal and molecular structure of the inclusion compound between 1,1′-binaphthyl-2,2′-dicarboxylic acid and acetylacetone (1∶1)

The lattice type crystalline inclusion compound of 1,1′-binaphthyl-2,2′-dicarboxylic acid (BNDA) with acetylacetone (AcAc) 1∶1 has been investigated by single crystal X-ray diffraction. AcAc is present as the enolic tautomer, stabilized by a notably short intramolecular hydrogen bond. This H-bond closes a six-membered ring with delocalization of the system of conjugated double bonds. In the crystal the AcAc molecules are incorporated into channels, delimited by bulky binaphyl moieties, in a hydrogen-bonded framework of BNDA, and they do not show any disorder. The strictly stoichiometric host:guest ratio seems to be enforced by packing forces only.

Supramolecular complexation of DMF and acetone involving singly bridged triarylmethanol and analogous hosts

Abstract DMF and acetone inclusions with the 2,7-dibromo-9-phenylfluoren-9-ol host (1) and the DMF complexes of the 13-phenyl- (2) and 13-(phenyl-ethynyl)- (3) derivatives of the 1,3,5-tribenzocycloheptatriene-13-ol hosts have been studied by X-ray diffraction. All four complexes contain hydrogen bonded (1:1) host-guest associates, which build up the crystal structures by ordinary van der Waals forces, occasionally supported by weak C-H…O interactions. The host-guest aggregates in the 1·DMF (1:1) and the 1·acetone (1:1) compounds show very similar geometry, possibly enforced by the packing forces. The host 2 molecules in the 2·DMF (1:1) complex are arranged so as to form endless tunnels in which the disordered DMF guests reside. The DMF complex of the slightly helical 3 [3·DMF 1:1)] crystallizes with a chiral space group symmetry (P21).

Inclusion compounds of cis- and trans-3,3-bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid hosts with ethanol guests. Crystal structures and selective inclusion modes

Structures of the crystalline inclusion complexes of cis- and trans-3,3-bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid hosts, 1 and 2, have been studied by X-ray diffraction. Crystal data: 1·EtOH (1 : 1), monoclinic, C2/c, a= 21.9870(7), b= 10.7398(3), c= 18.2478(4)A, β= 110.46(2)°, Z= 8, R= 0.051 for 2085 reflections collected at room temperature. 2·EtOH (1 : 2), monoclinic, P21/c, a= 14.619(2), b= 11.032(2), c= 15.595(3)A, β= 116.37(1)°, Z= 4, R= 0.052 for 1881 reflections collected at 173(1) K. The molecular geometries of 1 and 2 are rather similar, but 1 behaves as a monofunctional host owing to the intramolecular hydrogen bond between the two carboxyl groups, whereas 2 is a typical bifunctional host, as revealed by the different host: guest stoichiometries. Both hosts form endless H-bonded chains with ethanol guests, but the chains are differently organized: 1 creates supramolecular helices with alcoholic guests, whereas the H-bond scheme in 2·EtOH (1 : 2 ) is characterized by closed loops of hydrogen bonds.

Small-ring inclusion hosts. 4. X-ray crystal structures oftrans-3,3-Bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid and of its inclusion complex with Dimethyl Sulphoxide (1:2)

AbstractThe crystal structures of the unsolvatedtrans-3,3-bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid (1) and of its inclusion compound with dimethyl sulphoxide,1·DMSO (1:2), have been studied by X-ray diffraction. Crystals of1 show triclinic symmetry (P

Crystalline alcoholic inclusions of singly-bridged triarylmethanol hosts. Synthesis, X-ray crystal structures and binding modes of five inclusion compounds

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Crystalline host-guest complexes involving carboxylic acid hosts and a dimethyl sulphoxide guest. X-ray crystal structures of two inclusion species

) withZ = 4 and the unit cell dimensionsa = 7.617(2),b = 15.321(4),c = 15.297(3) Å,α = 109.76(2),β = 103.47(1),γ = 89.87(2)°. FinalR = 0.037 for 3601 reflections collected atT = 153(1) K. Crystals of1·DMSO (1: 2) are monoclinic (P21/n) withZ = 4 and cell dimensionsa = 10.744(1),b = 10.806(1),c = 21.302(2) Å,β = 101.68(1)°. The clathrate structure was refined toR = 0.034 for 1671 reflections obtained atT = 173(1) K. In the unsolvated host compound cyclic pairs of O-H ... bonds, commonly observed in carboxylic acids, couple the carboxylic functions two by two, thus giving rise to endless chains due to the bifunctionality and thetrans position of the acid groups of1. The complex with DMSO as guest, however, consists of distinct hydrogen-bonded 1:2 host-guest associates, held together by weak intermolecular interactions.