ABSTRACT
The title compound, C17H21NO2, was synthesized by the reaction of (1R)-(+)-3-benzyl-camphor and hydroxyl-amine. The oxazole ring makes a dihedral angle of 23.42â (16)° with the phenyl ring. The six-membered ring of the norboryl group adopts a boat conformation, whereas each of the five-membered rings of the norboryl group displays a flattened envelope conformation, with the C atom carrying the methyl groups representing the flap for both rings. In the crystal, mol-ecules are linked into zigzag chains propagating along the b axis by O-Hâ¯N hydrogen bonds.
ABSTRACT
In the title hydrated mol-ecular salt, [Fe(C12H8N2)3](C9H5N4O)2·0.5H2O, the water mol-ecule site is half-occupied. The Fe-N bond lengths within the octa-hedral tris-chelate [Fe(phen)3](2+) ion (phen is 1,10-phenantroline) are indicative of a low-spin d(6) electronic configuration for the metal ion. The C-N, C-C and C-O bond lengths in the polynitrile anions indicate extensive electronic delocalization. In the crystal, the components are linked through O-Hâ¯N hydrogen bonds, forming [100] chains, as well as through Coulombic inter-actions.
ABSTRACT
Single crystals of Ca(5)Zr(3)F(22), penta-calcium trizirconium docosafluoride, were obtained unexpectedly by solid-state reaction between CaF(2) and ZrF(4) in the presence of AgF. The structure of the title compound is isotypic with that of Sr(5)Zr(3)F(22) and can be described as being composed of layers with composition [Zr(3)F(20)](8-) made up from two different [ZrF(8)](4-) square anti-prisms (one with site symmetry 2) by corner-sharing. The layers extending parallel to the (001) plane are further linked by Ca(2+) cations, forming a three-dimensional network. Amongst the four crystallographically different Ca(2+) ions, three are located on twofold rotation axes. The Ca(2+) ions exhibit coordination numbers ranging from 8 to 12, depending on the cut off, with very distorted fluorine environments. Two of the Ca(2+) ions occupy inter-stices between the layers whereas the other two are located in void spaces of the [Zr(3)F(20)](8-) layer and alternate with the two Zr atoms along [010]. The crystal under investigation was an inversion twin.
ABSTRACT
The title compound, C(16)H(24)O(3), was synthesized from ilicic acid which was isolated from the aerial part of Inula Viscosa- (L) Aiton [or Dittrichia Viscosa- (L) Greuter]. The mol-ecule contains two fused six-membered rings both in chair conformations. In the crystal, mol-ecules are linked into chains running parallel to the a axis by O-Hâ¯O hydrogen bonds.
ABSTRACT
The title compound, C(19)H(29)NO(6), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methyl-ene-3,14-dioxatricyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule contains a fused five- and ten-membered ring system. The ten-membered ring adopts an approximate chair-chair conformation, while the five-membered ring is in an envelope conformation, with the C atom closest to the hy-droxy group forming the flap. In the crystal, weak C-Hâ¯O hydrogen bonds connect the mol-ecules into layers parallel to (001). An intra-molecular O-Hâ¯N hydrogen bond is also present.
ABSTRACT
The title compound, C(19)H(29)O(4), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methylen-3,14-dioxatricyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule is built up from two fused five- and ten-membered rings with the pyrrolidin-1-ylmethyl group as a substituent. The five-membered lactone ring has an envelope conformation, whereas the ten-membered and pyrrolidine rings display approximate chair-chair and twisted conformations, respectively. The dihedral angle between the ten-membered ring and the lactone ring is 18.01â (19)°. An intra-molecular O-Hâ¯N hydrogen bond occurs. The crystal structure is stabilized by weak inter-molecular C-Hâ¯O hydrogen-bonding inter-actions.
ABSTRACT
The title compound, C(15)H(15)NO, which was synthesized under solvent-free conditions by the reaction of acetoacetone and 2-naphthyl-amine, adopts a Z conformation about the C=C bond. The enamine-ketone fragment is approximately planar [maximum deviation = 0.026â (3)â Å] and forms a dihedral angle of 39.78â (3)° with the naphthalene ring system. An intra-molecular N-Hâ¯O hydrogen bond is observed.
ABSTRACT
The title compound, C(19)H(29)NO(5), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methyl-ene-3,14-dioxatricyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule is built up from two fused five- and ten-membered rings with the (pyrrolidin-4-yl)methyl group as a substituent. The two five-membered ring display the same envelope conformations, whereas the ten-membered ring adopts an approximate chair-chair conformation. The dihedral angle between the ten-membered ring and the lactone ring is 21.81â (9)°. An intra-molecular O-Hâ¯N hydrogen bond stabilizes the mol-ecular conformation. In the crystal, inter-molecular C-Hâ¯O inter-actions link the mol-ecules into chains parallel to the c axis.
ABSTRACT
The title compound, C(21)H(25)ClO, was semi-synthesized from isocostic acid, isolated from the aerial part of Inula Viscosa- (L) Aiton [or Dittrichia Viscosa- (L) Greuter]. The cyclo-hexene ring has a half-chair conformation, whereas the cyclo-hexane ring displays a chair conformation.
ABSTRACT
The title compound, C(22)H(28)O, was isolated from the aerial part of Inula viscosa- (L) Aiton [or Dittrichia viscosa- (L) Greuter]. The cyclo-hexene ring has a half-chair conformation, whereas the cyclo-hexane ring displays a chair conformation being substituted at position 2 by a 3-(4-methyl-phen-yl)prop-2-enoyl group. In the crystal, weak inter-molecular C-Hâ¯O hydrogen bonds link mol-ecules into chains in the [010] direction.
ABSTRACT
The title compound, C(21)H(27)NO(4), was synthesized from 9α-hy-droxy-parthenolide, which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The asymmetric unit contains two independent mol-ecules. In each, the ten-membered ring displays an approximative chair-chair conformation. Each of the five-membered rings adopts a flattened envelope conformation, the C(H)-C-C(H) atoms representing the flap lie out of the mean plane through the remaining four atoms by 0.443â (2) and 0.553â (2)â Å. The dihedral angle between the least-squares planes through the ten- and five-membered rings in the two mol-ecules are similar [22.54â (17) and 23.39â (14)°]. In the crystal, mol-ecules are linked by O-Hâ¯O, O-Hâ¯N and N-Hâ¯O hydrogen bonds.
ABSTRACT
The title compound, C(16)H(24)Cl(2)O, was synthesized from ß-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzocyclo-heptene), which was isolated from essential oil of the Atlas cedar (Cedrus atlantica). The two fused rings exhibit different conformations: the six-membered ring has a screw-boat conformation, while the seven-membered ring displays a boat conformation. The dihedral angle between the two rings is 56.56â (18)°. In the crystal, mol-ecules aggregate into supra-molecular chains along the c axis mediated by O-Hâ¯O hydrogen bonds.
ABSTRACT
The title compound, C(16)H(23)Cl(2)NO, was synthesised from ß-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzocyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The mol-ecule contains a seven membered ring, which is fused to a five- and a three-membered ring. The five-membered ring has a twisted conformation, whereas the seven-membered ring displays a chair conformation. The dihedral angle between the five- and seven-membered rings is 45.26â (9)°. The absolute structure was established unambiguously from anomalous dispersion effects. In the crystal, mol-ecules are linked into chains propagating along the b axis by inter-molecular N-Hâ¯O hydrogen bonds; an intramolecular N-Hâ¯O link also occurs.
ABSTRACT
The title compound, C(25)H(34)N(2)O(5), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methyl-ene-3,14-dioxatricyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule contains a fused five- and ten-membered ring system. The ten-membered ring adopts an approximate chair-chair conformation, while the five-membered ring is in an envelope conformation, with the C atom closest to the hy-droxy group forming the flap. The piperazine ring is in a chair conformation. In the crystal, O-Hâ¯O hydrogen bonds connect mol-ecules into chains along [100]. Weak inter-molecular C-Hâ¯O hydrogen bonds are also present.
ABSTRACT
The title compound, C(20)H(31)NO(5), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo-[9.3.0.0(2),(4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The mol-ecule is built up from fused five-and ten-membered rings with the pipyridin-1-yl-methyl group as a substituent. The ten-membered ring adopts an approximate chair-chair conformation, while the six- and five-membered rings display chair and envelope conformations, respectively. The dihedral angle between the mean planes of the ten-membered ring and the lactone ring is 20.8â (3)°. An intra-molecular O-Hâ¯N hydrogen-bond occurs. The crystal structure is stabilized by weak inter-molecular C-Hâ¯O hydrogen bonds.
ABSTRACT
Single crystals of the title compound, Al(2)P(6)O(18), were obtained by solid-state reaction. The monoclinic structure is isotypic with its Cr(III), Ga(III) and Ru(III) analogues and is built up of six-membered phosphate ring anions, P(6)O(18) (6-), isolated from each other and further linked by isolated AlO(6) octa-hedra by sharing corners. Each AlO(6) octa-hedron is linked to four P(6)O(18) (6-) rings. More accurately, two rings are linked through bidentate diphosphate groups attached in the cis-positions to the AlO(6) octa-hedron. The other two rings are linked to the two remaining corners, also in cis-positions of the AlO(6) octa-hedron.
ABSTRACT
Single crystals of the title compound, NaTb(PO(3))(4), were obtained by solid-state reaction. This compound belongs to type II of long-chain polyphosphates with the general formula A(I)B(III)(PO(3))(4). It is isotypic with the NaNd(PO(3))(4) and NaEr(PO(3))(4) homologues. The crystal structure is built up of infinite crenelated chains of corner-sharing PO(4) tetra-hedra with a repeating unit of four tetra-hedra. These chains, extending parallel to [100], are linked by isolated TbO(8) square anti-prisms, forming a three-dimensional framework. The Na(+) ions are located in channels running along [010] and are surrounded by six oxygen atoms in a distorted octa-hedral environment within a cut-off distance <2.9â Å.
ABSTRACT
Single crystals of the title compound, K(2)Al(2)P(8)O(24), were obtained by solid-state reaction. The monoclinic structure is isotypic with that of the Ga(III) analogue and is built of eight-membered phosphate ring anions P(8)O(24) (8-) (2/m symmetry) isolated from each other and further linked by isolated AlO(6) octa-hedra ( symmetry) by sharing corners. Each AlO(6) octa-hedron is linked to four P(8)O(24) (8-) rings in such a way that two rings are linked through bidentate diphosphate groups attached in the cis positions on two opposite parallel edges of the octa-hedron. The two other rings are linked via corner-sharing to the two remaining corners in the trans positions of the AlO(6) octa-hedron. Each P(8)O(24) (8-) ring anion is linked to eight AlO(6) octa-hedra. More accurately, each ring anion is linked to four AlO(6) octa-hedra through bidentate diphosphate groups attached in the cis positions to the AlO(6) octa-hedron and to the four remaining octa-hedra by sharing corners. This three-dimensional linkage delimits channels running parallel to [001] in which the ten-coordinated K(+) cations (2 symmetry) are distributed over two columns. These columns alternate with empty octa-gonally-shaped channels expanding through the P(8)O(24) (8-) ring anions.
ABSTRACT
Single crystals of the title compound, potassium praseodymium(III) polyphosphate, were obtained by solid-state reaction. The monoclinic non-centrosymmetric structure is isotypic with all other KLn(PO(3))(4) analogues from Ln = La to Er, inclusive. The crystal structure of these long-chain polyphosphates is built up from infinite crenelated polyphosphate chains of corner-sharing PO(4) tetra-hedra with a repeating unit of four tetra-hedra. These chains, running along [100], are arranged in a pseudo-tetra-gonal rod packing and are further linked by isolated PrO(8) square anti-prisms [Pr-O = 2.3787â (9)-2.5091â (8)â Å], forming a three-dimensional framework. The K(+) ions reside in channels parallel to [010] and exhibit a highly distorted coordination sphere by eight O atoms at distances ranging from 2.7908â (9) to 3.1924â (11)â Å.
ABSTRACT
Single crystals of the title compound, K(2)[Ni(H(2)O)(6)][ZrF(6)](2), were grown by slow evaporation of a 40% aqueous HF solution in which a stoichiometric mixture of NiCl(2)·6H(2)O, ZrF(4) and KCl was dissolved. The monoclinic structure is isotypic with its K(2)Cu, K(2)Zn, Cs(2)Zn and Cs(2)Cu analogues. The structure is built up from isolated, slightly elongated octa-hedral [Ni(H(2)O)(6)](2+) complex cations (symmetry ) and dimeric [Zr(2)F(12)](4-) complex anions (symmetry ) that are also isolated from each other. The [Zr(2)F(12)](4-) anion results from the association of two distorted penta-gonal-bipyramidal [ZrF(7)] coordination polyhedra by sharing an equatorial edge passing through an inversion center of the unit cell. Both isolated [Ni(H(2)O)(6)](2+) and [Zr(2)F(12)](4-) complex ions are situated in planes parallel to (010). They are connected by the eight-coordinated K(+) ions into a three-dimensional structure. An intricate O-Hâ¯F hydrogen-bonding network consolidates the structure.
