Dichloridobis(pyridine-2-thiol­ato-κ²N,S)tin(IV): a new polymorph

The title compound, [SnCl₂(C₅H₄NS)₂], is the product of reaction of 2,2′-dipyridyl disulfide with tin tetra­chloride. The Sn^IV atom adopts a distorted octa­hedral geometry, with the two bidentate pyridine-2-thiol­ate ligands forming two planar four-membered chelate rings. The two Sn—Cl, two Sn—N and two Sn—S bonds are in cis, cis and trans configurations, respectively. The crystal grown from acetonitrile represents a new monoclinic polymorph in space group C2/c with the mol­ecule having twofold rotational symmetry, the Sn^IV atom lying on the twofold axis. The mol­ecular structure of the monoclinic polymorph is very close to that of the triclinic polymorph studied previously in space group P-1, the mol­ecule occupying a general position [Masaki & Matsunami (1976). Bull. Chem. Soc. Jpn, 49, 3274–3279; Masaki et al. (1978). Bull. Chem. Soc. Jpn, 51, 3298–3301]. Apparently, the formation of the two polymorphs is determined by the different systems of inter­molecular inter­actions. In the crystal of the monoclinic polymorph, mol­ecules are bound into ribbons along the c axis by C—H...Cl hydrogen bonds, whereas in the crystal of the triclinic polymorph, mol­ecules form chains along the a axis by attractive S...S inter­actions. The crystal studied was a pseudo-merohedral twin; the refined BASF value is 0.221 (1).

[Bis(pyridin-2-yl) selenide-κ²N,N′]tetra­chloridotin(IV)

The title compound, [SnCl₄(C₁₀H₈N₂Se)], was obtained by the reaction of 2,2′-dipyridyl diselenide with tin tetra­chloride. The Sn^IV ion is coordinated by two N atoms [Sn—N = 2.266 (2) and 2.274 (2) Å] from the bis­(2-pyrid­yl)selenide ligand and four chloride anions [Sn—Cl = 2.3717 (6)–2.3939 (6) Å] in a distorted octa­hedral geometry. The central six-membered chelate ring has a boat conformation with the Se and Sn atoms deviating by 0.692 (3) and 0.855 (3) Å, respectively, from the mean plane through the remaining four ring atoms. The pyridine rings are inclined to each other by a dihedral angle of 49.62 (8)°. The crystal packing exhibits short inter­molecular Se...Cl contacts [3.5417 (7) and 3.5648 (7) Å], weak C—H...Cl hydrogen bonds and π–π stacking inter­actions between the pyridine rings with a centroid–centroid distance of 3.683 (3) Å.

Potassium [(1S)-1-azido-2-phenyl­eth­yl]trifluorido­borate

The title compound, K⁺·C₈H₈BF₃N₃⁻, is a salt containing the chiral organic trifluorido­borate anion. The organic anions and potassium cations are tightly bound to each other by the coordination K—F [2.654 (3)–3.102 (3) Å] and K—N [2.951 (4)–3.338 (4) Å] inter­actions. Thus, the potassium cation adopts a nine-vertex coordination polyhedron, which can be described as a distorted monocapped tetra­gonal anti­prism. In the crystal, the organic anions and potassium cations form layers parallel to (001). Weak C—H...π inter­actions between neighbouring phenyl rings further stabilize the crystal.

[N-(1-Aza­nidyl-2,2,2-trichloro­ethyl­idene)-2,2,2-trichloro­ethanimidamide]­copper(II)

The title compound, [Cu(C₄H₂Cl₆N₃)₂], was obtained by the reaction of CCl₃CN with ammonia in presence of CuCl. The Cu^II atom is located about an inversion centre. The mol­ecule consists of three planar units (one central square CuN₄ and two C₂N₃ fragments), adopting a staircase-like structure. The six-membered metallocycles have a sofa conformation with the Cu atom out of the plane of the 1,3,5-triaza­penta­dienyl ligands by 0.246 (5) Å. The ipso-C atoms of the CCl₃ substituents are slightly out of the 1,3,5-triaza­penta­dienyl planes by 0.149 (6) and −0.106 (6) Å. The CCl₃ groups of each 1,3,5-triaza­penta­dienyl ligand are practically in the energetic­ally favourable mutually eclipsed conformation. In the crystal, the mol­ecules are packed in stacks along the a axis. The mol­ecules in the stacks are held together by two additional axial Cu...Cl inter­actions of 3.354 (2) Å. Taking the axial Cu...Cl inter­actions into account, the Cu^II atom exhibits a distorted [4 + 2]-octa­hedral coordination environment. The stacks are bound to each other by weak inter­molecular attractive Cl...Cl [3.505 (2)–3.592 (3) Å] inter­actions.

1-Methyl-2,3-dihydro-1H-benzimidazole-2-selone

The title compound C₈H₈N₂Se, is the product of the reaction of 2-chloro-1-methyl­benzimidazole with sodium hydro­selenide. The mol­ecule is almost planar (r.m.s. deviation = 0.041 Å) owing to the presence of the long chain of conjugated bonds (Se=C—NMe—C=C—C=C—C=C—NH). The C=Se bond length [1.838 (2) Å] corresponds well to those found in the close analogs and indicates its pronounced double-bond character. In the crystal, mol­ecules form helicoidal chains along the b axis by means of N—H...Se hydrogen bonds.

Dimethyl 2-[23-oxo-22,24-diphenyl-8,11,14-trioxa-25-aza­tetra­cyclo­[19.3.1.0^2,7.0^15,20]penta­cosa-2,4,6,15(20),16,18-hexaen-25-yl]but-2-enedioate

The title compound, C₃₉H₃₇NO₈, is a product of the Michael addition of the cyclic secondary amine subunit of aza-14-crown-4 ether to dimethyl acetyl­enedicarboxyl­ate. The piperidinone ring exhibits a distorted chair conformation and the dimethyl acetyl­enedicarboxyl­ate fragment has a cis configuration with a dihedral angle of 56.61 (5)° between the two carboxyl­ate groups. The crystal packing is stabilized by the weak C—H...O hydrogen bonds.

Dimethyl 2-[22,24-dimethyl-23-oxo-8,11,14-trioxa-25-aza­tetra­cyclo­[19.3.1.0^2,7.0^15,20]penta­cosa-2,4,6,15(20),16,18-hexaen-25-yl]but-2-enedioate

The title compound, C₂₉H₃₃NO₈, is a product of the Michael addition of the cyclic secondary amine subunit of the aza-14-crown-4 ether to dimethyl acetyl­enedicarboxyl­ate. The piperidinone ring exhibits a distorted chair conformation, and the dimethyl ethylenedicarboxylate fragment has a cis configuration with a dihedral angle of 78.96 (5)° between the two carboxyl­ate groups. The crystal packing is stabilized by weak C—H...O hydrogen bonds.

24-Acetyl-8,11,14-trioxa-24,27-diaza­penta­cyclo­[19.5.1.1^22,26.0^2,7.0^15,20]octa­cosa-2,4,6,15(20),16,18-hexaen-28-one

The title compound, C₂₅H₂₈N₂O₅, is a product of the Petrenko–Kritchenko condensation of N-acetyl­piperidone with 1,5-bis­(2-formyl­phen­oxy)-3-oxapentane and ammonium acetate. The mol­ecule comprises a fused penta­cyclic system containing an aza-14-crown-3-ether macrocycle, two piperidone and two benzene rings. The aza-14-crown-3-ether ring adopts a bowl conformation. The dihedral angle between the benzene rings fused to the aza-14-crown-4-ether unit is 70.18 (4)°. The central piperidone ring has a boat conformation, whereas the terminal piperidone ring adopts a chair conformation. The conformation of the central piperidone ring is determined by two intra­molecular N—H...O hydrogen bonds. In the crystal, mol­ecules are linked by weak C—H...O inter­actions into chains along [010].

Dimethyl 2-[24-acetyl-28-oxo-8,11,14-trioxa-24,27-diaza­penta­cyclo­[19.5.1.1^22,26.0^2,7.0^15,20]octa­cosa-2,4,6,15(20),16,18-hexaen-27-yl]but-2-enedioate

The title compound, C₃₁H₃₄N₂O₉, is a product of the Michael addition of the cyclic secondary amine subunit of the (bis­pidino)aza-14-crown-4 ether to dimethyl acetyl­ene­dicarboxyl­ate. The mol­ecule comprises a tricyclic system containing the aza-14-crown-3 ether macrocycle and two six-membered piperidinone rings. The aza-14-crown-3-ether ring adopts a bowl conformation with a dihedral angle between the planes of the fused benzene rings of 51.14 (5)°. The central piperidone ring has a boat conformation, whereas the terminal piperidone ring adopts a chair conformation. The dimethyl ethyl­enedicarboxyl­ate fragment has a cis configuration with a dihedral angle of 56.56 (7)° between the two carboxyl­ate groups. The crystal packing is stabilized by weak C—H...O hydrogen bonds.

meso-(1S*,21R*)-25-Methyl-8,11,14-trioxa-22,24,25-triaza­tetra­cyclo­[19.3.1.0^2,7.0^15,20]penta­cosa-2,4,6,15(20),16,18-hexa­ene-23-thione chloro­form monosolvate

The title compound crystallizes as a chloro­form solvate, C₂₀H₂₃N₃O₃S·CHCl₃, with two crystallographically independent units. The independent units have distinctly different inter­action patterns between the aza­crown macrocycle and the chloro­form solvent mol­ecule. In one of them, the chloro­form mol­ecule forms C—H...N and Cl...H—C hydrogen bonds with the aza­crown macrocycle (as a proton donor and an acceptor, respectively), whereas in the other, one of the chloro­form mol­ecules is bound to the aza­crown macrocycle by an attractive Cl...O [3.080 (3) Å] inter­action. The aza­crown macrocycles of different units are structurally similar; the aza-14-crown-3-ether ring adopts a bowl conformation with dihedral angles between the planes of the fused benzene rings of 60.7 (1) and 68.0 (1)°. The triazinane­thione ring in both cases has a sofa conformation. The crystal packing is characterized by N—H...S, N—H...O, C—H...Cl and C—H...S hydrogen bonds.

(3aS,4S,6S,7aR)-Hexahydro-3a,5,5-trimethyl-2-phenyl-4,6-methano-1,3,2-benzodioxaborole

The mol­ecule of the title compound, C₁₆H₂₁BO₂, comprises a chiral fused tricyclic system containing five-membered (1,3,2-dioxaborolane), six-membered (cyclo­hexa­ne) and four-membered (cyclo­butane) rings. The 1,3,2-dioxaborolane ring is almost planar (r.m.s. deviation = 0.035 Å), and the syn H and Me substituents at this ring are in an eclipsed conformation. The cyclo­hexane and cyclo­butane rings adopt sofa and butterfly conformations, respectively. The B atom has a trigonal–planar configuration (sum of the bond angles = 360.0°). The phenyl ring is practically coplanar with the 1,3,2-dioxaborolane ring [dihedral angle between the ring planes = 1.96 (8)°]. The absolute structure was determined from the known configuration of (+)-pinanediol which was used in the synthesis. In the crystal, weak C—H...π(Ph) inter­actions occur.

3-Methyl-1,2,3,4,5,6,1′,2′,3′,4′-deca­hydro­spiro­[benz[f]isoquinoline-1,2′-naphthalen]-1′-one

The title compound, C₂₃H₂₃NO, is the product of a tandem transformation of the double Mannich base bis­(1-oxo-1,2,3,4-tertrahydro-2-naphtho­ylmeth­yl)amine hydro­chloride in HBr solution upon heating. The tetra­hydro­pyridine ring has a non-symmetrical half-chair conformation, whereas the cyclo­hexa­diene and cyclo­hexene rings adopt non-symmetrical half-boat conformations. The dihedral angle between the planes of the terminal benzene rings is 62.85 (6)°. The N atom has a trigonal–pyramidal geometry [sum of the bond angles = 332.4 (3)°]. In the crystal, mol­ecules form [001] chains via weak non-classical C—H...N hydrogen bonds. The chains are stacked along the b axis.

Pyridine-2,5-diamine

In the title mol­ecule, C₅H₇N₃, intra­cyclic angles cover the range 117.15 (10)–124.03 (11)°. The N atoms of the amino groups have trigonal–pyramidal configurations deviating slightly from the pyridine plane by 0.106 (2) and −0.042 (2) Å. In the crystal, the pyridine N atom serves as an acceptor of an N—H...N hydrogen bond which links two mol­ecules into a centrosymmetric dimer. Inter­molecular N—H...N hydrogen bonds between the amino groups further consolidate the crystal packing, forming a three-dimensional network.

6-Methyl­pyridin-2-amine

In the title mol­ecule, C₆H₈N₂, the endocyclic angles are in the range 118.43 (9)–122.65 (10)°. The mol­ecular skeleton is planar (r.m.s. deviation = 0.007 Å). One of the two amino H atoms is involved in an N—H...N hydrogen bond, forming an inversion dimer, while the other amino H atom participates in N—H...π inter­actions between the dimers, forming layers parallel to (100).