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  • Author: Christian Näther x
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Abstract

Six isostructural inclusion compounds of various ketone and ether guest molecules into the hydrogen-bonded host-matrix of N,N’-ditosyl-p-phenylenediamine are presented. Crystal growth, structure determinations as well as the arrangement within the clathrates formed is reported and discussed in detail. Packing coefficients and especially the volume ratios between the guest-containig channels and the unit cells allow to estimate the size-limit of guest molecules, which can cocrystallize. Additional crystal growth experiments yield information concerning other types of guest molecules, inclusion from solvent mixtures and guest removal as well as guest exchange processes observed for the N,N′-ditosyl-p-phenylenediamine host matrix.

In a study preceeding the investigation of a novel class of inclusion compounds, the lowtemperature crystal structure o f the host-m olecule N ,N ’-ditosyl-p-phenylenediamine has been determined. It crystallizes in the monoclinic space group P21/N with two formula units in the unit cell, forming layers of hydrogen-bonded molecules. The essential subunits are rigid phenyl rings and flexible sulfonamide linkages C -N(H)-S(O2)-C, the conformations o f which are discussed by comparison with data from the Cambridge Structural Database and based on density functional theory (DFT) as well as semiempirical PM3 calculations for the selected model compounds, N-methyl-methane-, N-methyl-benzene- and N-phenyl-methane-sulfonamide. The torsion angle dependent energy and enthalpy profiles allow estimates o f the rotational barriers around the C -S-N -C bonds. In addition, potential hydrogen bonding by the host molecule is discussed in comparison to analogous carbonic acid derivatives.

In an 8-dimethylamino-naphth-1-yl-phosphorane a dative N→P bond forms in spite of the spacer properties of the naphthalene skeleton. Its “normal” length, 213.2 pm, much too short to fill the perispace, forces the C10 skeleton into severe distortion. In the light of these properties peri distances d(N-P/Si) ≫250 pm in 8-dimethylamino-naphth-1-yl-phosphines, -silanes etc. are recognized as evidence for steric hindrance

Abstract

The 31P NMR data of non-quaternary (8-dimethylamino-naphth-1-yl)phosphonium salts, with emphasis on the 1J(31P, 1H) coupling constants, where scrutinized for their potential to yield information about N→P dative interactions. As for δ (29Si) and 1J(29Si, 1H) in the isosteric silanes, the data do not permit conclusions in favour of such interactions. 1J(31P, 1H) of bis(8-dimethylaminonaphth- 1-yl)phosphine in conjunction with the distances d(N···P) invalidates the basic assumption on which the claim of dative N→P/Si bonding in such phosphorus and silicon compounds rests, viz. that N···P/Si distances of ca. 270 pm are evidence for P/Si-hypercoordination. No evidence for hydrogen bonds N···H-P was found.

Abstract

Basic principles of hyrogen-bonding are reviewed including cooperative effects and within the novel class of inclusion compounds formed by N,N′-ditosyl-p-phenylenediamine as a capable host, four aggregates with the hydrogen donor or acceptor guest molecules morpholine, pyridine, N,N-dimethylformamide and dimethylsulfoxide are reported. Morpholine introduces three additional hydrogen bonds N-H···N, N-H···O as well as C-H···O and pyridine, DMF and DMSO each one of type N-H···N, N-H··O(=C) and N-H···O(=S ). Crystallization and structures determined are discussed in detail with special emphasis on the varying sulfonamide conformation as well as on cavity or channel inclusion of the guest molecules. In conclusion, the crystal growth conditions and the structures of the altogether 13 N,N′-ditosyl-p-phenylenediamine inclusion compounds investigated are reviewed and possible reasons for their formation are discussed.

Abstract

The new compound {Mn(dien)2}2[MnSb2S7] (dien = diethylenetriamine) was obtained under solvothermal conditions and crystallizes in the orthorhombic space group Pbca. The main structural motif is the [MnSb2S7]4– anion being constructed by a [MnS4]6– tetrahedron, a [SbIIIS3]3– and a [SbVS4]3– anion. Each thioantimonate anion shares one edge with the Mn2+ centered cation generating the [MnSb2S7]4– unit. The two independent Mn2+ cations in the two {Mn(dien)2}2+ complexes are in a distorted octahedral environment of two tridentate acting dien molecules. One cation displays the λδλλ-conformation and the other the δλλδ-conformation. Several intermolecular S···H—N bonding interactions are found between the cations and the anions.

The 1,2,3,4-tetraphenyl-shielded sodium cyclopentadienide, Na[HC5 (C6H5)4], demonstrates essential facets of structure-determining cation solvation. The following solvent-shared or solvent-separated ion multiples have been crystallized from the respective aprotic ether solutions and structurally characterized: [(C29H21 )Na(THF)7/2], [(C29H21 )Na(DME)2]. [(C29H21 )][Na(diglyme)2], [(C29H21 )][Na(triglyme)2] and, from 18-crown-6 solution, the novel tripeldecker ion triple, [(C29H21 )][Na(18-crown-6)Na(18-crown-6)Na(18-crown-6)]⊕⊕, which contains two Na counter cations between three 18-crown-6 discs. The structures, discussed in comparison with literature data and based on MNDO calculations, demonstrate the essential effects of Na counter cation solvation by various ether ligands.

Abstract

The title compound has been synthesized under solvothermal conditions by the reaction of elemental chromium, antimony and selenium in a solution of 40% 1,2-ethanediamine (en) in methanol. The crystal structure consists of tetrahedral SbSe4 3- anions which are connected by monoprotonated 1,2-ethanediamine (enH+) cations via N-H--Se hydrogen bonding. The enH+ cations are joined via strong N-H -N hydrogen bonds between the ammonium hydrogen and the amino nitrogen atom forming four distinct chains, each built up of three crystallographically independent enH+ cations. Two of these chains are running parallel to [100], the other two are parallel to [010]. Based on this arrangement different centrosymmetric or non-centrosymmetric hydrogen bonding patterns are possible, but only in one chain the sequence of NH2 and NH3 + groups was determined by X-ray diffraction

The ligand-rich precursor compound tetra-μ-chloro-bis (μ2-2,3-dimethylpyrazine)-tetrakis-(acetonitrile-N)tetracopper(I) (1) was prepared by the reaction of CuCl with 2,3-dimethylpyrazine in acetonitrile. On heating this compound decomposes quantitatively in a single step directly to the ligand-deficient coordination polymer di-μ3-chloro-(μ2-2,3-dimethylpyrazine-N,N′)copper(I).