Least-squares Plane Research Articles

(5-Bromo-2-meth-oxy-phen-yl)(4-ethyl-cyclo-hex-yl)methanone.

In the title compound, C16H21BrO2, the cyclo­hexane ring is in a chair conformation and its least-squares plane is at an angle of 61.3 (9)° to the benzene ring. The crystal packing is stabilized by weak π–π stacking inter­actions [centroid–centroid distance = 3.697 (9) Å] between the bromo­meth­oxy­phenyl rings of neighbouring mol­ecules.

(2E)-2-(2-Phenylhydrazin-1-ylidene)propanoic acid

The 13 non-H atoms comprising the title compound, C9H10N2O2, are close to planar (r.m.s. deviation = 0.140 Å), with maximum deviations of 0.292 (1) and 0.210 (1) Å to either side of the least-squares plane exhibited by the hy­droxy and carbonyl O atoms, respectively. The observed conformation is stabilized by an intra­molecular O—H⋯N hydrogen bond. The conformation about the N=C double bond [1.2909 (16) Å] is E. The hy­droxy OH group also forms an inter­molecular hydrogen bond to a carbonyl O atom, and the amine H atom similarly forms an N—H⋯O hydrogen bond to a second carbonyl O atom. The result is the formation of a double layer with a flat topology. Layers stack along the a-axis direction connected by C—H⋯π inter­actions.

(S)-[5-Methyl-3-(3-methylthiophen-2-yl)-4,5-dihydroisoxazol-5-yl]methanol

In the title compound, C10H13NO2S, the thio­phene and isoxazoline rings are almost coplanar, the dihedral angle between their least-squares planes being 2.08 (1)°. The O—H atoms of the methyl hy­droxy group and the N atom of the isoxazole ring are orientated in the same direction to allow for the formation of inter­molecular O—H⋯N hydrogen bonds that lead to a supra­molecular chain along the a axis.

3-Cyclohexylsulfinyl-5-iodo-2-methyl-1-benzofuran

There are two independent mol­ecules, A and B, in the asymmetric unit of the title compound, C15H17ClO2S, in each of which the cyclo­hexyl ring adopts a chair conformation. The benzofuran units in each mol­ecule are essentially planar, with mean deviations from a least-squares plane defined by the nine constituent ring atoms of 0.006 (2) Å for A and 0.011 (2) Å for B. In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯O and C—H⋯π inter­actions and by two I⋯O contacts [I⋯O = 3.079 (2) and 3.017 (2) Å].

Study of Nα-benzoyl-L-argininate ethyl ester chloride, a model compound for poly(ester amide) precursors: X-ray diffraction, infrared and Raman spectroscopies, and quantum chemistry calculations

Poly(ester amide)s (PEAs) are lacking in structural and spectroscopic information. This paper reports a structural and spectroscopic characterization of N(α)-benzoyl-L-argininate ethyl ester chloride (BAEEH(+)·Cl(-)), an important amino acid derivative and an adequate PEAs' model compound. Crystals of BAEEH(+)·Cl(-) obtained by slow evaporation in an ethanol∕water mixture were studied by different complementary techniques. X-ray analysis shows that BAEEH(+)·Cl(-) crystallizes in the chiral space group P2(1). There are two symmetry independent cations (and anions) in the unit cell. The two cations have different conformations: in one of them, the angle between the least-squares planes of the phenyl ring and the guanidyl group is 5.1(2)°, and in the other the corresponding angle is 13.3(2)°. There is an extensive network of H-bonds that assembles the ions in layers parallel to the ab plane. Experimental FT-IR and Raman spectra of BAEEH(+)·Cl(-) were recorded at room temperature in the 3750-600 cm(-1) and 3380-100 cm(-1) regions, respectively, and fully assigned. Both structural and spectroscopic analysis were supported by quantum chemistry calculations based on different models (in vacuo and solid-state DFT simulations).

(2E)-3-{4-[(1H-1,3-Benzimidazol-2-yl)methoxy]-3-ethoxyphenyl}-1-(4-bromophenyl)prop-2-en-1-one monohydrate

In the title compound, C25H21BrN2O3·H2O, the benzimidazole fragment and the water mol­ecule of crystallization are each disordered over two sets of sites of equal occupancy. The dihedral angles between the least-squares planes of the benzimidazole and the 3-eth­oxy- and 4-bromo­benzene rings are 86.9 (6) and 85.1 (1)°, respectively in one disorder component. The crystal packing is stabilized by inter­molecular O—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds, which link the mol­ecules into chains along the a axis.

5-Cyclohexyl-3-cyclohexylsulfonyl-2-methyl-1-benzofuran

In the title compound, C21H28O3S, the benzofuran unit is essentially planar, with a mean deviation of 0.016 (1) Å from the least-squares plane defined by the nine constituent atoms. Both cyclo­hexane rings adopt chair conformations.

Ethyl 1-benzoyl-4-hydroxy-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate

In the title compound, C27H25NO4, the tetra­hydro­pyridine ring adopts a half-chair conformation. The three phenyl rings form dihedral angles of 66.33 (7), 87.36 (8) and 36.90 (7)° with the least-squares plane through the tetra­hydro­pyridine ring. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯O hydrogen bond, generating an S(6) motif.

{rac-5-[Methoxy(phenyl)methyl]-10,20-diphenylporphyrinato}nickel(II)

The title compound, [Ni(C40H28N4O)], was obtained from a Grignard reaction of the respective formyl­porphyrin to yield {5-[hy­droxy(phen­yl)meth­yl]-10,20-diphenyl­porphyrinato}nickel(II), followed by crystallization from methyl­ene chloride/methanol. The mol­ecule exhibits a ruffled macrocycle with an average deviation of the 24 macrocycle atoms from their least-squares plane (Δ24) of 0.26 Å and an average Ni—N bond length of 1.931 (2) Å. In line with the asymmetrical substituent pattern, the degree of distortion is slightly larger at point of attachment of the meth­oxy(phen­yl)methyl residue than at the unsubstituted meso position. The meth­oxy group attached to the chiral C atom is disordered in a 0.534 (4):0.466 (4) ratio.

2-[(4-Methylphenyl)sulfanyl]aniline

The least-squares planes defined by the aromatic moieties in the title aniline derivative, C13H13NS, are nearly perpendicular to each other, forming a dihedral angle of 87.80 (7)°. Apart from a weak intramolecular N—H⋯S hydrogen bond, a co-operative set of N—H⋯N hydrogen bonds present in the crystal structure leads to the formation of tetra­meric units.

1-(3-Chlorophenyl)-4,4,6-trimethyl-3,4-dihydropyrimidine-2(1H)-thione

In the title compound, C13H15ClN2S, the dihydro­pyrimidine ring is essentially planar, with a maximum deviation from the least-squares plane of 0.122 (3) Å for the unsubstitued olefinic C atom. The dihedral angle between the dihydro­pyrimidine and benzene rings is 86.62 (13)°. The crystal structure is stabilized by inter­molecular N—H⋯S hydrogen bonds, which form centrosymmetric dimers arranged along the c axis.

{2-[(Benzo-yloxy)meth-yl]-1-oxo-3H-pyrrolizin-2-yl}methyl benzoate.

The title compound, C23H19NO5, was prepared by esterification of 2,2-bis­(hy­droxy­meth­yl)-2,3-dihydro-1H-pyrrolizin-1-one with benzoyl chloride in pyridine·The pyrrolizine ring system is approximately planar with a maximum deviation of 0.008 (2) Å from the least-squares plane; the two phenyl rings are oriented at dihedral angles of 64.26 (11) and 70.75 (10)° with respect to the pyrrolizine ring system. Weak inter­molecular C—H⋯O hydrogen bonding occurs in the crystal structure.

6-Meth-oxy-4-methyl-2H-chromen-2-one.

The whole mol­ecule of the title coumarin derivative, C11H10O3, is approximately planar, with a maximum deviation of 0.116 (3) Å from the least-squares plane defined by all non-H atoms. In the crystal, adjacent mol­ecules are linked into chains along [011] via inter­molecular C—H⋯O hydrogen bonds.

2-[(E)-2-Hydroxy-5-(trifluoromethoxy)benzylideneamino]-4-methylphenol

The title compound, C15H12F3NO3, is a Schiff base which adopts the cis-quinoid form in the solid state. The dihedral angle between the least-squares planes of the benzene rings being 3.6 (1)°. The F atoms of the –CF3 group are disordered over two sets of sites with refined occupancies of 0.61 (5) and 0.39 (5). An intra­molecular N—H⋯O hydrogen bond occurs. The crystal structure is stabilized by inter­molecular O—H⋯O hydrogen bonds.

Bis(tetrabutylammonium) bis(3,4,5-trioxocyclopent-1-ene-1,2-dithiolato-κ2S,S′)cadmate(II) 0.25-hydrate

The title compound, (C16H36N)2[Cd(C5O3S2)2]·0.25H2O, contains two disordered tetra­butyl­ammonium cations, a complex [Cd(C5O3S2)2]2− anion and a 0.25-hydrate water. The anion is composed of a bidentate coordinated 3,4,5-trioxocyclo­pent-1-ene-1,2-dithiol­ate (dtcroc) group forming a distorted tetra­hedral configuration around the CdII ion. The dihedral angle between the least-squares planes of the ten-atom sulfur-substituted croconate groups in the anion is 84.10 (8)°. The crystal packing is stabilized by weak C—H⋯O and C—H⋯S cation–anion hydrogen-bond inter­actions. In each of the two cations one butyl group is disordered over two positions in the ratios 0.589 (11):0.411 (11) and 0.796 (12):0.204 (12).

N,N′-Bis(3-phenylprop-2-en-1-ylidene)-2,2′-disulfanediyldianiline

In the title compound, C30H24N2S2, the two phenyl rings attached to the S atoms are oriented nearly perpendicularly, making a dihedral angle of 86.14 (8)°. Each of the two ArCH=CHCH=N units is almost planar, having maximum deviations from the least-squares planes of 0.125 and 0.149 Å, and rotated around the C—N bonds relative to the adjacent phenyl ring by 110.26 and 30.30°.

Phenylhydrazinium (6-carboxypyridine-2-carboxylato)(pyridine-2,6-dicarboxylato)cobaltate(II)–pyridine-2,6-dicarboxylic acid–water (1/1/3)

The asymmetric unit of the title compound, (C6H9N2)[Co(C7H3NO4)(C7H4NO4)]·C7H5NO4·3H2O, contains one (6-carb­oxy­pyridine-2-carboxyl­ato)(pyridine-2,6-dicarboxyl­ato)cobaltate(II) anion, one phenyl­hydrazinium cation, one pyridine-2,6-dicarb­oxy­lic acid mol­ecule and three uncoordin­ated water mol­ecules, part of which are disordered. The CoII ion is coordinated by a pyridine-2,6-dicarboxyl­ate ion and a 6-carb­oxy­pyridine-2-carboxyl­ate ligand almost perpendicular to each other [the angle between the least-squares planes is 87.38 (4)°] and is surrounded by two O atoms and two N atoms in the equatorial plane and two O atoms in axial positions, resulting in a distorted octa­hedral coordination geometry. There is an extensive three-dimensional network of O—H⋯O and N—H⋯O hydrogen bonds, which link the components.

Ethyl 3,6-di-O-benzyl-2-deoxy-N-phthalimido-1-thio-β-D-glucopyranoside

In the title compound, C30H31NO6S, the plane of the N-phthalimido group is nearly orthogonal to the least-squares plane of the sugar ring (defined by atoms C2, C3, C5 and O5 using standard glucose nomenclature), making a dihedral angle of 72.8 (1)°. The thio­ethyl group has the exo-anomeric conformation. The hy­droxy group forms an inter­molecular hydrogen bond to the O atom in the sugar ring, generating [100] chains. There are four close π–π contacts with centroid–centroid distances less than 4.0 Å, all with dihedral angles between the inter­acting π systems of only ≃ 8°, supporting energetically favourable stacking inter­actions.

9-(2,4-Dichlorophenyl)-3,3,6,6-tetramethyl-3,4,5,6-tetrahydro-9H-xanthene-1,8(2H,7H)-dione

The title compound, C23H24Cl2O3, was synthesized by reaction of 2,4-dichloro­benzaldehyde and 5,5-dimethyl­cyclo­hexane-1,3-dione in ethyl­ene glycol. The central ring of the xanthene moiety is almost planar (with an r.m.s. deviation of 0.0268 Å from the least-squares plane) while the two outer rings, in a cis arrangement, display envelope conformations. The ring of the 2,4-dichloro­phenyl substituent is nearly perpendicular [85.89 (4)°] to the xanthene ring system.

Trans-2-(2-Nitro-1-phenylethyl)cyclohexanone

In the title compound, C14H17NO3, the plane of the phenyl ring and the least-squares plane of the cyclo­hexyl moiety enclose an angle of 89.14 (6)°. The cyclohexyl ring adopts a chair conformation. In the crystal, the molecules are linked by weak C—H⋯O bonds, with each of the nitro-O atoms accepting two such interactions.