Methyl 2-[(ferrocenylcarbonyl)amino]thio­phene-3-carboxyl­ate

The title compound, [Fe(C₅H₅)(C₁₂H₁₀NO₃S)], was synthesized from ferrocenecarboxylic acid and methyl 2-amino­thio­phene-3-carboxyl­ate in modest yield. The substituted ring system is essentially planar through the amido­thienylcarboxyl­ate moiety, η⁵-(C₅H₄)CONH(C₄H₂S)CO₂Me, with the amido unit at an angle of 3.60 (7)° to the five-atom thienyl group, which is oriented at an angle of 3.17 (7)° to the ester moiety. The primary hydrogen bond is an intramolecular N—H...O=C_{carboxyl­ate} interaction [N...O 2.727 (2) Å], and the main intermolecular hydrogen bond involves a thienyl carboxyl­ate and the carboxyl­ate of a symmetry-related molecule [C...O 3.443 (3) Å].

Methyl­chloro­sila­[1]­ferrocenophane

In the title compound, [Fe(C₁₁H₁₁ClSi)], the cyclo­penta­dienyl ligands are tilted towards the bridging Si atom, with a tilt angle of 19.4 (3)°.

(4-tert-Butyl­phenyl)­phospha­[1]­ferrocenophane

In the title structure, [Fe(η-C₅H₄)₂P{p-C₆H₅-C(CH₃)₃}] or [Fe(C₂₀H₂₁P)], the cyclo­penta­dienyl (Cp) rings of the ferrocenophane are tilted towards the bridging P atom, with a tilt angle of 26.9 (3)°. Weak intermolecular C—H...π(Cp-ring) interactions link mol­ecules into sheets parallel to the bc plane.

Octaaquatetrakis(μ₂-2,6-diform­yl-4-methyl­phenolato)­tetra-μ₃-hydroxo-tetraneodymium(III) trifluoro­methane­sulfonate butanol disolvate tetra­hydrate

The title compound, [Nd₄(μ₃-OH)₄(μ₂-C₉H₇O₃)₄(H₂O)₈](CF₃SO₃)₄·2C₄H₁₀O·4H₂O, was synthesized from Nd(CF₃SO₃)₃ and 2,6-diform­yl-4-methyl­phenol at relatively high pH. The cation, which lies on a crystallographic twofold axis, features a cubane-type [Ln₄(OH)₄]⁸⁺ core of four Nd^III cations and four μ₃-OH ligands occupying alternate vertices of a distorted cube.

Bis(μ-2,6-di­formyl-4-methyl­phenolato)­bis­[bis(2,6-di­formyl-4-methyl­phenolato)­neodymium(III)]

The title compound, [Nd₂(C₉H₇O₃)₆], crystallizes from an an­hydro­us alcoholic mixture of neodymium perchlorate, 2,6-di­formyl-4-methyl­phenol and sodium hydro­xide. The structure consists of discrete dinuclear mol­ecules with Nd^III ions in eightfold coordination environments. The complete mol­ecule is generated from the asymmetric unit by a crystallographic center of symmetry. Intramolecular and intermolecular π–π stacking and C—H...O interactions help to stabilize the crystal packing.

Redetermination of para-amino­pyridine (fampridine, EL-970) at 150 K

The structure of fampridine (EL-970) or 4-amino­pyridine, C₅H₆N₂, has been redetermined at 150 K. The room-temperature structure has been reported previously [Chao & Schempp (1977). Acta Cryst. B33, 1557–1564]. Pyramidalization at the amine N atom occurs in fampridine, with the N atom 0.133 (11) Å from the plane of the three C/H/H atoms to which it is bonded; the inter­planar angle between the pyrid­yl ring and NH₂ group is 21 (2)°. Aggregation in the solid state occurs by N—H...N and N—H...π(pyridine) inter­actions with N...N and N...π(centroid) distances of 2.9829 (18) and 3.3954 (15) Å, respectively; a C—H...π(pyridine) contact completes the inter­molecular inter­actions [C...π(centroid) = 3.6360 (16) Å].

The two-dimensional structure of poly[[diperchloratocopper(II)]-bis­[μ₂-1,3-bis­(4-pyrid­yl)propane]]

In the crystal structure of the title compound, [Cu(ClO₄)₂(C₁₃H₁₄N₂)₂]_n, there are two independent Cu^II ions, one of which occupies a crystallographic inversion center. The 1,3-bis­(4-pyrid­yl)propane ligands bridge the Cu^II ions to form two independent two-dimensional sheets. In addition, two terminal perchlorate anions are coordinated to each Cu^II ion, resulting in distorted octa­hedral coordination around each Cu^II ion. The equatorial Cu—N bonds are in the range 2.014 (4)–2.031 (4) Å, while the long axial Cu—O distances range from 2.434 (3) to 2.548 (3) Å.

Tris(2-N-methyl­amino­carbonyl-3-hydr­oxy-1,6-dimethyl-1,4-dihydro-4-pyridinonato)­iron(III) dimethyl­formamide disolvate

In the crystal structure of the title compound, Fe(C₉H₁₁N₂O₃)₃·2C₃H₇NO, the Fe^III ion is six-coordinate with a distorted octa­hedral configuration consisting of six donor O atoms from three bidentate ligands. Two of the amide NH groups are involved in intra­molecular N—H...O_p (p = phenolic) hydrogen bonds, while the third is involved in forming centrosymmetric dimers via inter­molecular N—H...O_p hydrogen bonds.

Tris(1-cyclo­propyl-6-methyl-2-(N-methyl­amino­carbonyl)-4-oxo-1,4-dihydro­pyridin-4-olato)iron(III) dimethyl­formamide sesquisolvate dihydrate

In the crystal structure of the title compound, [Fe(C₁₁H₁₃N₂O₃)₃]·1.5C₃H₇NO·2H₂O, the Fe^III ion is six-coordinated in a distorted octa­hedral configuration consisting of six donor O atoms from three bidentate ligands. The Fe complex crystallizes with two mol­ecules of water and one and a half mol­ecules of dimethyl­formamide (DMF). The three amino­carb­oxy groups (CONHCH₃) are all rotated out of the planes of their respective pyridinone rings. Inter­molecular O—H...O and N—H...O hydrogen bonds contribute to the stabilization of the crystal structure.

(S,S)-N,N′-Dicyano­ethyl-1,2-(2-hydroxyphenyl)ethyl­enediamine

In the title mol­ecule {systematic name: 3,3′-[1,2-bis­(2-hydroxy­phen­yl)ethane-1,2-diyldiimino]propane­nitrile}, C₂₀H₂₂N₄O₂, there are three different types of intra­molecular hydrogen bonds, one of each of the types N—H...O [H...O = 2.51 (3) Å], N—H...N [H...N = 2.21 (3) Å] and O—H...N [H...O = 1.71 (3) Å]. In the crystal structure, mol­ecules are linked into one-dimensional chains in the a-axis direction via inter­molecular O—H...N [H...N = 1.95 (4) Å] hydrogen bonds.