Use of polar maps in conformational analysis

Ounsworth, J. P.; Weller, L.

doi:10.1021/ed064p568

Cited by 14 publications

(10 citation statements)

References 3 publications

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“…We use skeletal drawings, which include only the donor atoms of the ligands (12),-to reveal the topographies of the donor atoms about the guest cations. We next present the 18 torsion angles of a macrocycle on a polar-coordinate map (16 formations of many 18-crown-6 metal cation complexes (1 8). We offer this method as an alternative to the torsion-anglesequence methods of Stoddart (19) and Dale (20).…”

mentioning

confidence: 99%

Solid-state chemistry of polycarboxylate crown ether cation complexes: cooperative binding of water and metal ions by flexible chorands

Dutton¹,

Fyles²,

Suresh³

et al. 1993

Can. J. Chem.

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The solid-state structures of alkali-metal salt complexes of crown ether tetra-and hexa-carboxylic acids (18C6A4 and 18C6A6) have been determined. The sodium salt of 18C6A6 crystallizes as the trihydrate in orthorhombic space group P2,2,2, (a = 7.6868(12), b = 15.429(3), c = 21.975(2) A, R = 0.031 for 5192 observed data); the potassium salt of 18C6A6 crystallizes as the the trihydrate in orthorhombic space group P2,2,2, (a = 7.671 1(8), b = 15.709(2), c = 21.966(5) A, R = 0.035 for 2521 observed data); the thallium(1) salt of 18C6A6~rystallizes as the dihydrate in orthorhombic space group P2,2,2, (a = 12.0331(10), b = 12.4333(12), c = 17.366(2) A, R = 0.035 for 4952 observed data); and the cesium salt of 18C6& crystallizes as the dihydrate in monoclinic space group P2, (a = 7.708(3), b = 13.492(2), c = 11.9501(9) A, P = 94.49(2)", R = 0.029 for 4480 observed data). The sodium salt of 18S6A4 crystallizes as the dihydrate in monoclinic space group P2, (a = 11.4368(1 I), b = 7.7068(1 l), c = 12.6579(12) A, P = 98.515(8)", R = 0.035 for 3000 observed data); the thallium(1) salt ofo18C6A4 crystallizes as the dihydrate in monoclinic space group P2,(a = 11.719(2), b = 7.668(2), c = 12.8403(13) A, P = 99.052(9)", R = 0.040 for 3981 observed data); and the cesium saltoof 18C6A4 crystallizes as the dihydrate in monoclinic space group P2, (a = 11.787(2), b = 7.637(2), c = 13.001(2) A, p = 98.705(12)", R = 0.038 for 3428 observed data). Both chorands exhibit a cooperative relationship of mean cavity radius and guest-ion radius, which closely follows the effective ionic radii of the guests. The hexaacid is a preorganized host for monohydrated cations. It provides a trigonal hydrogen bonding receptor site for the water molecule, and up to nine oxygen donors for cation binding. Guests ranging in size from ~a ' to CS' are accommodated without distortion of the macrocyclic framework. The tetraacid is similarly tolerant of a range of guests, but greater structural reorganization of the ligand is required to optimize contacts with fully dehydrated cations. Skeletal drawings of donor atoms, in conjunction with polar coordinate maps of torsion angles, reveal how the demands of the guest are accommodated by the host. (2) A, p = 98,705(12)" et R = 0,038 pour 3428 donnees observees. Les deux chorands presentent une relation cooperative des rayons moyens de cavite et d'ion invite qui suit de trks prks celle des rayons ioniques effectifs des invites. L'hexaacide est un hBte preorganise pour les cations monohydrates. I1 fournit aux molCcules d'eau un site recepteur pour une liaison hydrogkne trigonale et jusqu'a neuf oxygenes donneurs pour des liaisons avec les cations. Les invites dont la taille se situe entre celles du Na' et du Cs+ s'accommodent sans distorsions dans la structure macrocyclique. Le tetraacide tolere aussi une grande variCtC d'invites; toutefois, une plus grande reorganisation structurale est requise du ligand pour optimiser les contacts avec les cations complktement deshydrates. Des diagrammes du squelette des atomes d...

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confidence: 99%

Solid-state chemistry of polycarboxylate crown ether cation complexes: cooperative binding of water and metal ions by flexible chorands

Dutton¹,

Fyles²,

Suresh³

et al. 1993

Can. J. Chem.

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“…The corresponding carbon dilide 1,8-dioxacyclotetradecane-2,9-dione (Groth, 1985), as well as tridecanolactone (Wiberg et al, 1991), both crystallize in the [3434] conformation. The latter diamond-lattice conformation is also preferred by the parent hydrocarbon cyclotetradecane (Ounsworth & Weiler, 1987). Molecularmechanics calculations (Mohamadi, 1990) showed that the X-ray conformation is 10 kJ above the global minimum.…”

Section: Data Collectionmentioning

confidence: 99%

1,8-Dioxa-4,11-dithiacyclotetradecane-2,9-dione

2001

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The title compound, C10H16O4S2, was formed in a reaction of allyl alcohol and thioglycolic acid followed by acid‐catalyzed esterification of the resulting hydroxy acid. The compound forms triclinic crystals and there is an inversion center in the middle of the molecule The structure was determined to be a 14‐membered dilide which in the solid state assumes a centrosymmetric conformation where the S—C—C—O—C—C—C—S chain is roughly gauche‐gauche‐anti‐anti‐gauche‐anti‐gauche. Molecular‐mechanics calculations showed that the X‐ray conformation is 10 kJ above the global minimum.

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“…4 (Dunsworth & Weiler, 1987). The conformational analysis of the macrocyclic polyether 18-crown-6 presented by Dobler (1984) Fig.…”

Section: Conformations Of Macrocyclic Rings In (2) and (3)mentioning

confidence: 99%

Bond length–bond order relations and calculated geometries for some benzenoid aromatics, including phenanthridine. Structures of 5,6-dimethylphenanthridinium triflate, [N-(6-phenanthridinylmethyl)-aza-18-crown-6-κ⁵ O,O',O'',O''',O''''](picrate-κ²-O,O')potassium, and [N,N'-bis(6-phenanthridinyl-κN-methyl)-7,16-diaza-18-crown-6-κ⁴ O,O',O'',O

Kiralj¹,

Kojić‐Prodić²,

Žinić³

et al. 1996

Acta Crystallogr Sect B

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The crystal structures of the title compounds are studied in order to investigate the role of novel fluoroionophores in complexation of sodium and potassium. In the potassium complex seven coordination, including the picrate ligand, is encountered. An additional coordination site is via the phenanthridine nitrogen at 3.252 (2)/~ (second coordination). The complex is of C1 symmetry and the aza-18-crown-6 macrocylic ring exhibits a crown-type conformation. The 7,16-diaza-18-crown-6 macrocycle accommodates a six-coordinate sodium with two additional ligands, via nitrogen from phenanthridine units. The complex cation shows a crystallographic twofold symmetry. The macrocycle is not of the crown-type conformation. In both complexes the alkali metals are shifted out of the cavity centres towards a picrate ligand in [N-(6-phenanthridinylmethyl

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Use of polar maps in conformational analysis

Cited by 14 publications

References 3 publications

Solid-state chemistry of polycarboxylate crown ether cation complexes: cooperative binding of water and metal ions by flexible chorands

Solid-state chemistry of polycarboxylate crown ether cation complexes: cooperative binding of water and metal ions by flexible chorands

1,8-Dioxa-4,11-dithiacyclotetradecane-2,9-dione

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