In the title hydrated mol­ecular salt, [Fe(C12H8N2)3](C9H5N4O)2·0.5H2O, the water mol­ecule site is half-occupied. The Fe—N bond lengths within the octa­hedral 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—H⋯N hydrogen bonds, forming [100] chains, as well as through Coulombic inter­actions.

Single crystals of Ca5Zr3F22, penta­calcium trizirconium docosafluoride, were obtained unexpectedly by solid-state reaction between CaF2 and ZrF4 in the presence of AgF. The structure of the title compound is isotypic with that of Sr5Zr3F22 and can be described as being composed of layers with composition [Zr3F20]8− made up from two different [ZrF8]4− square anti­prisms (one with site symmetry 2) by corner-sharing. The layers extending parallel to the (001) plane are further linked by Ca2+ cations, forming a three-dimensional network. Amongst the four crystallographically different Ca2+ ions, three are located on twofold rotation axes. The Ca2+ ions exhibit coordination numbers ranging from 8 to 12, depending on the cut off, with very distorted fluorine environments. Two of the Ca2+ ions occupy inter­stices between the layers whereas the other two are located in void spaces of the [Zr3F20]8− layer and alternate with the two Zr atoms along [010]. The crystal under investigation was an inversion twin.

The title compound, C16H24O3, was synthesized from ilicic acid which was isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The mol­ecule contains two fused six-membered rings both in chair conformations. In the crystal, mol­ecules are linked into chains running parallel to the a axis by O—H⋯O hydrogen bonds.

The title compound, C19H29NO6, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule 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 hy­droxy group forming the flap. In the crystal, weak C—H⋯O hydrogen bonds connect the mol­ecules into layers parallel to (001). An intra­molecular O—H⋯N hydrogen bond is also present.

The title compound, C25H34N2O5, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule 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 hy­droxy group forming the flap. The piperazine ring is in a chair conformation. In the crystal, O—H⋯O hydrogen bonds connect mol­ecules into chains along [100]. Weak inter­molecular C—H⋯O hydrogen bonds are also present.

The title compound, C20H31NO5, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule 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 20.8 (3)°. An intra­molecular O—H⋯N hydrogen-bond occurs. The crystal structure is stabilized by weak inter­molecular C—H⋯O hydrogen bonds.

The title compound, C19H29O4, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methylen-3,14-dioxatricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule 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 18.01 (19)°. An intra­molecular O—H⋯N hydrogen bond occurs. The crystal structure is stabilized by weak inter­molecular C—H⋯O hydrogen-bonding inter­actions.

The title compound, C19H29NO5, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule 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 21.81 (9)°. An intra­molecular O—H⋯N hydrogen bond stabilizes the mol­ecular conformation. In the crystal, inter­molecular C—H⋯O inter­actions link the mol­ecules into chains parallel to the c axis.

The title compound, C15H15NO, which was synthesized under solvent-free conditions by the reaction of acetoacetone and 2-naphthyl­amine, adopts a Z conformation about the C=C bond. The enamine–ketone fragment is approximately planar [maximum deviation = 0.026 (3) Å] and forms a dihedral angle of 39.78 (3)° with the naphthalene ring system. An intra­molecular N—H⋯O hydrogen bond is observed.

The title compound, C21H27NO4, was synthesized from 9α-hy­droxy­parthenolide, which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The asymmetric unit contains two independent mol­ecules. 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 0.443 (2) and 0.553 (2) Å. The dihedral angle between the least-squares planes through the ten- and five-membered rings in the two mol­ecules are similar [22.54 (17) and 23.39 (14)°]. In the crystal, mol­ecules are linked by O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds.

The title compound, C22H28O, was isolated from the aerial part of Inula viscosa­ (L) Aiton [or Dittrichia viscosa­ (L) Greuter]. The cyclo­hexene ring has a half-chair conformation, whereas the cyclo­hexane ring displays a chair conformation being substituted at position 2 by a 3-(4-methyl­phen­yl)prop-2-enoyl group. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link mol­ecules into chains in the [010] direction.

The title compound, C21H25ClO, was semi-synthesized from isocostic acid, isolated from the aerial part of Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter]. The cyclo­hexene ring has a half-chair conformation, whereas the cyclo­hexane ring displays a chair conformation.

The title compound, C16H23Cl2NO, was synthesised from β-himachalene (3,5,5,9-tetra­methyl-2,4a,5,6,7,8-hexa­hydro-1H-benzocyclo­heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The mol­ecule 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 45.26 (9)°. The absolute structure was established unambiguously from anomalous dispersion effects. In the crystal, mol­ecules are linked into chains propagating along the b axis by inter­molecular N—H⋯O hydrogen bonds; an intramolecular N—H⋯O link also occurs.

The title compound, C16H24Cl2O, was synthesized from β-himachalene (3,5,5,9-tetra­methyl-2,4a,5,6,7,8-hexa­hydro-1H-benzocyclo­heptene), 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 56.56 (18)°. In the crystal, mol­ecules aggregate into supra­molecular chains along the c axis mediated by O—H⋯O hydrogen bonds.

Single crystals of the title compound, K2[Ni(H2O)6][ZrF6]2, were grown by slow evaporation of a 40% aqueous HF solution in which a stoichiometric mixture of NiCl2·6H2O, ZrF4 and KCl was dissolved. The monoclinic structure is isotypic with its K2Cu, K2Zn, Cs2Zn and Cs2Cu analogues. The structure is built up from isolated, slightly elongated octa­hedral [Ni(H2O)6]2+ complex cations (symmetry ) and dimeric [Zr2F12]4− complex anions (symmetry ) that are also isolated from each other. The [Zr2F12]4− anion results from the association of two distorted penta­gonal–bipyramidal [ZrF7] coordination polyhedra by sharing an equatorial edge passing through an inversion center of the unit cell. Both isolated [Ni(H2O)6]2+ and [Zr2F12]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—H⋯F hydrogen-bonding network consolidates the structure.

The title compound, C16H24Cl2O, was synthesized from β-himachalene (3,5,5,9-tetra­methyl-2,4a,5,6,7,8-hexa­hydro-1H-benzocyclo­heptene), which was isolated from the essential oil of the Atlas cedar (cedrus atlantica). The mol­ecule forms an extended sheet of two fused rings which exhibit different conformations. The six-membered ring has a half-chair conformation, while the seven-membered ring displays a chair conformation; the dihedral angle between the two rings is 38.2 (1)°.

Single crystals of α-Ba2P2O7, dibarium diphosphate, were obtained by solid-state reaction. The ortho­rhom­bic structure is isotypic with α-Sr2P2O7 and is the second polymorph obtained for this composition. The structure is built from two different BaO9 polyhedra (both with m symmetry), with Ba—O distances in the ranges 2.7585 (10)–3.0850 (6) and 2.5794 (13)–2.9313 (4) Å. These polyhedra are further linked by sharing corners along [010] and either edges or triangular faces perpendicularly to [010] to form the three-dimensional framework. This polyhedral linkage delimits large channels parallel to [010] where the P2O7 diphosphate anions are located. These groups (symmetry m) are characterized by a P—O—P angle of 131.52 (9)° and an eclipsed conformation. They are connected to the BaO9 polyhedra through edges and corners.

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(PO3)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 PO4 tetra­hedra with a repeating unit of four tetra­hedra. These chains, running along [100], are arranged in a pseudo-tetra­gonal rod packing and are further linked by isolated PrO8 square anti­prisms [Pr—O = 2.3787 (9)–2.5091 (8) 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 2.7908 (9) to 3.1924 (11) Å.

Single crystals of the title compound, K2Al2P8O24, were obtained by solid-state reaction. The monoclinic structure is isotypic with that of the GaIII analogue and is built of eight-membered phosphate ring anions P8O24 8− (2/m symmetry) isolated from each other and further linked by isolated AlO6 octa­hedra ( symmetry) by sharing corners. Each AlO6 octa­hedron is linked to four P8O24 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 octa­hedron. The two other rings are linked via corner-sharing to the two remaining corners in the trans positions of the AlO6 octa­hedron. Each P8O24 8− ring anion is linked to eight AlO6 octa­hedra. More accurately, each ring anion is linked to four AlO6 octa­hedra through bidentate diphosphate groups attached in the cis positions to the AlO6 octa­hedron and to the four remaining octa­hedra 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 octa­gonally-shaped channels expanding through the P8O24 8− ring anions.

Single crystals of the title compound, NaTb(PO3)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(PO3)4. It is isotypic with the NaNd(PO3)4 and NaEr(PO3)4 homologues. The crystal structure is built up of infinite crenelated chains of corner-sharing PO4 tetra­hedra with a repeating unit of four tetra­hedra. These chains, extending parallel to [100], are linked by isolated TbO8 square anti­prisms, 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 octa­hedral environment within a cut-off distance <2.9 Å.

Single crystals of the title compound, Al2P6O18, were obtained by solid-state reaction. The monoclinic structure is isotypic with its CrIII, GaIII and RuIII analogues and is built up of six-membered phosphate ring anions, P6O18 6−, isolated from each other and further linked by isolated AlO6 octa­hedra by sharing corners. Each AlO6 octa­hedron is linked to four P6O18 6− rings. More accurately, two rings are linked through bidentate diphosphate groups attached in the cis-positions to the AlO6 octa­hedron. The other two rings are linked to the two remaining corners, also in cis-positions of the AlO6 octa­hedron.

Single crystals of KEu(PO3)4, potassium europium(III) polyphosphate, were obtained by solid-state reactions. This monoclinic form is the second polymorph described for this composition and belongs to type IV of long-chain polyphosphates with general formula A I B III(PO3)4. It is isotypic with its KEr(PO3)4 and KDy(PO3)4 homologues. The crystal structure is built of infinite helical chains of corner-sharing PO4 tetra­hedra with a repeating unit of eight tetra­hedra. These chains are further linked by isolated EuO8 square anti­prisms, forming a three-dimensional framework. The K+ ions are located in pseudo-hexa­gonal channels running along [01] and are surrounded by nine O atoms in a distorted environment.

Single crystals of yttrium penta­phosphate(V), YP5O14, were obtained by solid-state reaction. The ortho­rhom­bic title compound belongs to the family of ultraphosphates and is the second polymorph of this composition. It is isotypic with its Ho and Er analogues. The structure contains two bridging Q 2-type PO4 tetra­hedra and one branching Q 3-type PO4 tetra­hedron, leading to infinite ultraphosphate ribbons running along the a axis. The coordination polyhedron around the Y3+ cation may be described as distorted bicapped trigonal-prismatic. The YO8 polyhedra are isolated from each other. They are linked by corner-sharing to the O atoms of six Q 2-type and of two Q 3-type PO4 tetra­hedra into a three-dimensional framework.