bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrostatic Potential Field and Nucleophilicity of 3, 5, 8, 10‐Tetramethyl‐aceheptylene
Authors: Almlöf Jan , Haselbach Edwin , Jachimowicz Felicjan , Kowalewski Jozef 
Published: December 2004

AbstractThe electrostatic potential (EP.) for aceheptylene (I) is calculated using ab‐initio wavefunctions. In addition, the EP. around I is approximated by a monopole expression, using wavefunctions from various semiempirical procedures as a basis. It is found that the previously noted discrepancy between the thoretical prediction of differential nuclophilicity of the individual unsaturated C‐atoms in 3,5,8,10‐tetramethyl‐aceheptylene(II) and the experimental results of protonation is removed, if instead of local atomic charges, the EP. around II, approximated by that of I is considered.
Umcyclopropanisierung bei der Tetrabromierung eines tricyclischen Ketons zu 3exo, 4endo, 6exo‐Tribrom‐7‐brommethyl‐1,5‐dimethyl‐tricyclo[3.2.1.02,7]octan‐8‐on
Authors: Peter‐Katalinič Jasna , Zsindely Janos , Schmid Hans , Oberhänsli Willi E. 
Published: December 2004

Transcyclopropanation during the Tetrabromination of a Tricyclic Ketone to 3 exo, 4 endo, 6exo‐Tribromo‐7‐bromomethyl‐1,5‐dimethyl‐tricyclo[3.2.1.02,7]octan‐8‐oneBromination of the tricyclic ketone 1 with an excess of bromine at low temperature gives in approximately 30% yield the highly crystalline tricyclic tetrabromide 2 (Scheme 1). The structure of 2 was established by NMR.‐ and especially X‐ray‐analysis (Fig.1).Treatment of 1 with 1 mol‐equ. of bromine gives an unstable dibromide, to which the structure 3 was assigned on the basis of its NMR.‐spectrum and its further bromination to 2 (Scheme 1). In the course of the tetrabromination of 1 the original cyclopropane ring is opened in the first step (1 → 3) and another cyclopropane ring is formed in the second step (3 → 2) (cf. Scheme 3).
Fluororganische Synthesen V Darstellung und Abwandlung von Chlorfluorcyclopropanen ‐ Ein gezielter Zugang zu Fluorallylalkoholen
Authors: Schlosser Manfred , Van Chau Le 
Published: December 2004

Fluoroorganic Syntheses V. Preparation and Transformation of Chlorofluorocyclopropanes. – A Selective Approach to Fluoroallylic AlcoholsChlorofluorocarbene addition to unsaturated compounds is particularly convenient and efficient in a two‐phase system. This method works satisfactorily even if the olefin carries base‐sensitive substituents. The resultant chlorofluorocyclopropanes can be ring‐opened by silver‐salt assisted acetolysis affording 2‐fluorallylacetates, which yield 2‐fluorallylic alcohols upon saponification.
Proof of the Existence of a Linear, Centrosymmetric Polyiodide Ion I: the crystal structure of Cu(NH3)4 I4
Authors: Dubler Erich , Linowsky Lothar 
Published: December 2004

AbstractTetrammine‐copper(II)‐tetraiodide Cu(NH3)4I4 crystallizes in the monoclinic space group C 2/m. The crystal structure has been determined from X‐ray diffractometer data and refined to Rw = 2.2%. Four coplanar nitrogen atoms and two axial iodine atoms form an octahedral coordination around Cu(II) with a pronounced 4 + 2 tetragonal distortion. A connection of the Cu(II) atoms by linear, centrosymmetric I polyiodide ions results in infinite chains of [Cu(NH3) I]‐units. The central I‐I‐bond distance in I is 2.802(1) Å; a considerable amount of I‐I bonding is indicated by the distance of 3.342(1) Å found for the terminal bonds. These intramolecular bond distances correspond to calculated I‐I‐bond orders of 0.80 and 0.43.
Ptérobiline et néoptérobilines, réactivité et structures
Authors: Choussy Michèle , Barbier Michel 
Published: December 2004

Pterobiline and neopterobilines, reactivity and structuresPterobiline (biliverdine IX γ) and the two neopterobilines: phorcabiline and sarpedobiline, are the three main bile pigments found in Lepidopters. Studies on the reactivity of pterobiline (1) and phorcabiline esters are reported. Preparation of derivatives, in vitro transformation of pterobiline into phorcabiline, analysis of the pigments and their derivatives by field desorption mass spectrometry and Fourier transform NMR., lead to the structure 5 for the dimethyl ester of phorcabiline. By a similar reaction, biliverdine IX δ (15) affords the neobiliverdine IX δ (16). Possibility of an easy formation of new tetrapyrrolic compounds in the IX γ and IX δ series is thus reported for the first time.
Photochemische Reaktionen. 83. Mitteilung. Verbindungen der 3,4‐Dihydrojonon‐Reihe als Modelle zur Photochemie γ, δ‐ bzw. δ, ϵ‐ungesättigter Ketone und Aldehyde
Authors: Zink Markus Peter , Wolf Hans Richard , Müller Ernst Peter , Schweizer Wolfhard Bernd , Jeger Oskar 
Published: December 2004

Compounds of the 3,4‐dihydro‐ionone series as models for the photochemistry of γ, δ‐ and δ,ϵ‐ unsaturated ketones and aldehydes.The photochemistry of γ, δ‐ and δ,ϵ‐unsaturated carbonyl compounds of the dihydro‐ionone series has been studied, with special attention to the investigation of oxetane formation versus hydrogen abstraction.UV.‐irradiation of the dihydro‐β‐ionone compounds with structure A (1, 7, 14, 18, 24, 29) led to isomeric ethers with structures B (2, 8, 15, 19, 25, 30), C (3, 9, 16, 20, 26, 31) and D (4, 21, 27), isomeric bicyclic alcohols with structure E (5, 10, 17, 22, 28), and photoreduction products with structure F (6, 11, 12, 13). Photolysis of dihydro‐γ‐ionone (32) gave a complex mixture containing fragmentation product 35, hydrocarbon 36, β‐ambrinol (34), oxetane 33, as well as dihydro‐β‐ionone (1) and three of its photoproducts (2, 3, 5). The dihydro‐α‐ionone compounds 37 and 40 gave mixtures of fragmentation products and the oxetanes 38 and 41. Irradiation of the side‐chain homologues 42 and 45 yielded 43, which photo‐cyclizes to 44. In contrast, 3, 4‐dihydro‐3′,4′‐dehydro‐β‐ionone (46) gave merely the isomeric open‐chain triene‐ketone 47.The structures assigned to the ethers 2, 3, 33, 38 and to the alcohols 5, 10, 13 could be confirmed by chemical reactions and mutual interconversions. The structure of the ether 21 had to be established by X‐ray analysis, details of which are described.A novel intramolecular hydrogen transfer is involved in formation of ethers B. The photocyclization A → D probably proceeds by addition of the carbonyl‐C atom to the double bond (A → h), followed by methyl (1 → 2)‐shift (h → i). Process A → h may also be involved in formation of compounds of type C and E.
The Chemical Ionization of Organic Compounds. 2nd Communication. Linear Alkyl Halides
Authors: Houriet Raymond , Gäumann Tino 
Published: December 2004

AbstractThe chemical ionization spectra of linear alkyl halides with up to nine carbon atoms have been studied using water as protonating agent. An alkyl ion with the same number of carbon atoms as the halide is produced. With more than six carbon atoms in the chain, fragmentation becomes important. The results show that excited hydronium ions participate as intermediates and the fragments of the resulting alkyl ions have branched structures.
Ammoniakverlust aus α,ω‐Alkandiaminen im Massenspektrometer. 22. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen
Authors: Mayerl Friedrich , Hesse Manfred 
Published: December 2004

Loss of ammonia from α,ω‐alkanediamines in the mass spectrometer.Under electron impact α,ω‐alkanediamines lose ammonia from the molecular ion. This fragmentation reaction is explained in the case of 1.4‐butanediamine (1) on the basis of the spectra of homologues and deuteriated derivatives. The reaction proceeds via neighbouring group participation; the mechanism is given in Scheme 1.
Azidiniumsalze. 16. Mitteilung [1]. Struktur‐Reaktivitätsbeziehungen in Serien quartärer N‐Heteroaromaten: Kinetik der Reaktion heterocyclischer Azidiniumsalze mit Sulfit‐Ionen
Authors: Hellrung Bruno , Balli Heinz 
Published: December 2004

Structure‐Reactivity‐Relationships in Series of Quaternary Heterocyclic Compounds: Reaction Kinetics of Heterocyclic Azidinium Salts with Sulfite Ions.Die Reaktion der Azidiniumsalze 1a–f mit Sulfit‐Ionen, die Isomerisierungs‐ und Zerfallsreaktion der entstandenen Sulfotriazene 4a–f und 5a–f wurden mittels kinetischer Methoden untersucht. Die Säuredissoziationskonstanten der Sulfotriazene 4a–f und 5a–f wurden bestimmt und die Geschwindigkeits‐ und Aciditätskonstanten mit σHet‐Werten korreliert.
Umwandlung des Tricyclo[5,4,0,03,9]undecadiengerüstes in das neue Octahydro‐2,5‐methano‐azulengerüst
Authors: Fráater György 
Published: December 2004

Transformation of the Tricyclo[5,4,0,03,9]undecadiene System into the new Octahydro‐2,5‐methano‐azulene System.1,3,6‐Trimethyl‐tricyclo[5.4.0.03,9]undeca‐5, 10‐dien‐2‐one (1) was successively treated with sodium amide in toluene, potassium hydroxide in water, LiAlH4 in ether and TsCl in pyridine to give the p‐toluenesulfonate 5 in 66% overall yield. The solvolysis of 5 resulted in the remarkably clean formation of 6, 8a‐dimethyl‐9‐methyl‐iden‐2,5‐methano‐1,2,3,3a,4,5,8,8a‐octahydroazulene (6). The carboxylic acid 3 upon treatment with thionylchlorid in benzene at 70° underwent a spontaneous intramolecular Friedel‐Crafts acylation to give 9 and 10 which have the same carbonskeleton as 6. The endo‐chloro configuration of 10 was demonstrated by reduction of 10 to 4; this reaction proceeds presumably through a reductive fragmentation, the stereoelectronic requirements of which are given in the endo‐isomer of 10 only.
Halogenierte Pyridine I. Die Herstellung von 3‐Halogenmethylpyridinen aus dimerem Acrylnitril
Authors: Fritz Hans , Weis Claus D. , Winkler Tammo 
Published: December 2004

Halogenated pyridines I. The synthesis of 3‐halogenomethyl pyridines from dimeric acrylonitrile.α‐Methyleneglutaronitril, a linear dimerization product of acrylonitrile is a cheap, commercially available starting material for a new synthesis of 3‐halogenomethyl‐2, 6‐dihalogeno‐ or 2,5,6‐trihalogenopyridines prepared in two and three step reactions, respectively. The properties of this new class of halogenated pyridines are discussed.
Über Pterinchemie. 55. Mitteilung [1]. Reindarstellung und Charakterisierung von 5,6,7,8‐Tetrahydro‐L‐neopterin und 5,6,7,8‐Tetrahydro‐D‐monapterin
Authors: Schircks Bernhard , Bieri Jost H. , Viscontini Max 
Published: December 2004

Preparation and characterisation of pure 5,6,7,8‐tetrahydro‐L‐neopterine und 5,6,7,8‐tetrahydro‐D‐monapterine.The synthesis of these two compounds, III and IV, is described, and their structures ascertained by means of 1H‐NMR., 13C‐NMR. and FD. spectroscopy. In particular the possibility of detecting diastereomeric pairs of types III and IV in 13C‐NMR. spectra is discussed.
Tetrazoloazines. 15N nuclear magnetic resonance and infrared absorption spectroscopy
Authors: Thétaz Célestin , Wehrli F. W. , Wentrup Curt 
Published: December 2004

AbstractThe reaction of 4‐chloro‐2‐phenylquinazoline with K15NN2 has been studied by 15N‐NMR. spectroscopy. 15N‐chemical shifts in 5‐phenyl‐1 (3)‐[15N]‐tetrazolo[1,5‐c]quinazoline and ‐Nα(Nγ)‐[15N]‐4‐azido‐2‐phenylquinazoline are reported. The characteristic IR. absorption frequencies of the tetrazole group have been determined in a series of annelated 15N‐labelled compounds. From these studies and the chemistry of the labelled tetrazoles, it is concluded that all haloazines examined react with KN3 by the direct nucleophilic substitution mechanism. An addition of nucleophile‐ring opening‐ring closure (ANRORC) mechanism was not observed. The synthesis of several 15N‐labelled tetrazoloazines is described.
Ein Tricarbonyleisen‐π‐Komplex mit einem Silacyclohexadienyl‐Liganden
Authors: Fink Walter 
Published: December 2004

A Tricarbonyl Iron‐π‐Complex with a Silacyclohexadienyl‐Ligand.The triphenylmethyl cation abstracts a hydride ion from 1,1‐dimethyl‐1‐silacyclohexa‐2,4‐diene‐tricarbonyl iron to give the 1,1‐dimethyl‐1‐silacyclohexadienyl‐tricarbonyl iron cation.
Electronic Structure, Molecular Conformation and Reactivity of Benzonorbornadiene Systems
Authors: Haselbach Edwin , Rossi Michel 
Published: December 2004

AbstractFrom the photoelectron spectra of benzonorbornadiene (1) and its 9‐isopropylidene derivative (2) the energy and an approximate wave function for the highest occupied orbitals is obtained. With these results the differential reactivity of the systems in Diels‐Alder additions with ‘inverse electron demand’ is discussed on the basis of frontier orbitals. For the ground state of 2 similar non‐bonded interactions between the isopropylidene unit and the double bond or the benzene ring are indicated. Conformational equilibria in 9‐aza derivatives of 1 are discussed in view of these findings.
15N‐NMR. A Method for Assigning Structure in Complexes of Unsymmetrical o, o′–Dihydroxydiarylazo–Ligands
Authors: Pregosin Paul S. , Steiner Eginhard 
Published: December 2004

AbstractThe 15N‐NMR. parameters of some Pt(II)complexes of unsymmetrical o, o′‐dihydroxydiarylazo‐ligands are shown to be useful in the solution of subtle structural problems.
Nachweis von Fragment‐Genesen im Massenspektrometer. 3. Mitteilung. Aminosäuresequenz‐Analyse in Oligopeptiden und Oligopeptid‐Gemischen mit Hilfe der DADI‐Massenspektrometrie
Authors: Schlunegger Urs Peter , Hirter Peter , von Felten Hans 
Published: December 2004

Detection of Fragment Genesis in the Mass Spectrometer. III. Analysis of Amino‐Acid Sequence in Oligopeptides and in Mixtures of Oligopeptides by DADI‐Mass Spectrometry.The amino acid sequence was analysed by DADI mass spectrometry in simple oligopeptides and in mixtures containing two or three peptides.
Selektive Synthesen mit Organometallen V: Trimethylsilylmethyl‐kalium und andere Spitzenkönner unter den Metallierungsmitteln
Authors: Hartmann Jürgen , Schlosser Manfred 
Published: December 2004

Trimethylsilylmethylpotassium and other outstanding metallating agents.For the metallation of allylic and benzylic positions, trimethylsilylmethylpotassium is the most powerful reagent. Butyllithium in the presence of potassium t‐butoxide however, can usually replace it. Olefinic and cyclopropane hydrogen atoms are most readily attacked by pentylsodium, especially if the reaction is carried out in presence of potassium t‐butoxide. Trimethylsilylmethylpotassium, however, will equally work if an activating group, such as methoxy, is present in the substrate. Generalisations concerning the metallation mechanisms are drawn.
A Stereospecific Synthesis of Vitamin A from 2,2,6‐Trimethyl‐cyclohexanone
Authors: Olson Gary L. , Cheung H.‐C. , Morgan Keith D. , Borer René , Saucy Gabriel 
Published: December 2004

AbstractAn efficient synthesis of all‐(E) vitamin A acetate from 2,2,6‐trimethyl‐cyclohexanone has been achieved via the intermediacy of 1‐(9‐acetoxy‐3, 7‐dimethyl‐nona‐3,5,7‐trien‐1‐ynyl)‐2,2,6‐trimethyl‐cyclohexanol (25), readily prepared in high yield by allylic rearrangement of tertiary propenols with glacial acetic acid. The key step in the synthesis is the transformation of 25 to the unsaturated ketone 27 (9‐acetoxy‐3,7‐dimethyl‐1‐(2,6,6‐trimethyl‐cyclohex‐1‐enyl)‐nona‐3,5,7‐trien‐ 2‐one) using a novel vanadium(V)‐catalysed rearrangement reaction. The carbonyl in 27 affords the means for the essential isomerization of the adjacent double bond to the (E) isomer and the product is readily transformed into the polyene by reduction and elimination. An overall yield of 18–31% of vitamin A acetate from 2,2,6‐trimethyl‐cyclohexanone has been realized.
Synthesis and Some Reactions of 2,4,6‐Cycloheptatrienethione
Authors: Dugger Harry A. , Dreiding André S. 
Published: December 2004

AbstractThe synthesis of 2,4,6‐cycloheptatrienethione (1) was accomplished by reaction of tropone and phosphorus pentasulfide. Although 1 proved to be extremely unstable in concentrated solution, its UV. spectrum was measured, the ε‐values being determined indirectly by hydrolysis to tropone. The proof of structure rests on analytical data, conversion to tropone oxime on reaction with hydroxylamine and reaction with the sodium salt of malonitrile to give 2‐amino‐3‐cyano‐3aH‐cyclohepta[b]thiophene (4) which rearranged on chromatography to give what is probably the corresponding 8H‐compound (5). On dissolving 1 in 95% sulfuric acid, a large hypsochromic shift in the UV. spectrum was observed, which may be due to the mercaptotropylium ion.
Rastronole A, B, C, D, E, F, G und H; eine Gruppe multioxygenierter Diterpenbitterstoffe der ent‐Kauran‐Reihe aus Englerastrum scandens ALSTON
Authors: Nomoto Kyosuke , Rüedi Peter , Hans Eugster Conrad 
Published: December 2004

Rastronols A, B, C, D, E, F, G, and H, a group of multioxygenated bitter principles with ent‐kaur‐16‐en‐15‐one structure from Englerastrum scandens ALSTON (Labiatae)We have isolated from the leaves of Englerastrum scandens from Kenya eight new, highly oxygenated ent‐kaur‐16‐en‐15‐ones named rastronol A, B, C, D, E, F, G, and H, and determined their structures mainly by spectroscopic techniques as 1, 8, 14, 17, 20, 29, 39, and 51 respectively.
Preparation of cyano‐substituted styryl and stilbenyl compounds
Authors: Coviello Vincenzo , Emil Siegrist Adolf 
Published: December 2004

Abstracto‐ und p‐Cyansubstituierte Toluol‐Derivate können mit Anilen aromatischer carbocyclischer oder heterocyclischer Aldehyde in Gegenwart von Dimethylformamid und Natriummethylat bei Raumtemperatur in die entsprechenden Styryl‐ bzw. Stillbenyl‐Verbindungen übergeführt werden (« Anil‐Synthese »). Zur Darstellung Cyan‐substituierter Bis‐styryl‐Verbindungen sind Schiffsche Basen aus aromatischen Dialdehyden und o‐Chloranilin ihrer guten Löslichkeit wegen besonders geeignet.
Photochemische Reaktionen. 89. Mitteilung [1]. Zur Photochemie konjugierter Epoxy‐diene I. Versuche mit (E),β‐Jonyliden‐epoxiden
Authors: Peter Alder Alex , Richard Wolf Hans , Jeger Oskar 
Published: December 2004

Photolysis of conjugated epoxy‐dienesUV.‐irradiation (λ = 254 nm) of (E),β‐ionylidene‐epoxide (3) in n‐pentane gives the isomeric cyclopropene‐ketone 7 (90%) in a hitherto unreported type of photoreaction. The methylsubstituted (E),β‐ionylidene‐epoxide 6, however, undergoes (E/Z)‐photoisomerization to the (Z),β‐ionylidene‐epoxide 8 (91%).
Cytochalasin B (Phomin): Abbaureaktionen und Cyclisierung der B‐Cytochalasinsäure zu 21,22‐Dihydro‐isocytochalasin A
Authors: Scherling Dietrich , Csendes Ivan , Tamm Christoph 
Published: December 2004

Cytochalasin B (Phomin): Degradation Reactions and Cyclization of B‐Cytochalasinic Acid to 21,22‐Dihydro‐Isocytochalasin ATreatment of the γ‐lacton 5, a transformation product of cytochalasin B (phomin) (1), with OsO4 gave the dihydroxy derivatives 6 and 7. Cleavage of the former by NaIO4 in aqueous methanol yielded a mixture of the dimethylacetal 10 and the unsaturated aldehyde 11, which are potential intermediates for a total synthesis of cytochalasins. Cytochalasin B (1) was hydrolysed with NaOH in aqueous dioxane to B‐cytochalasinic acid (14). Recyclization of 14 using the Mukaiyama‐Corey method [19] [20] did not yield cytochalasin B (1) but the isomeric 21,22‐dihydro‐isocytochalasin A (18). Treatment of 14 according to Gerlach [21] yielded the phthalimidine 19.
Versuche zur Redox‐Simulation der photochemischen A/D‐Secocorrin → Corrin‐Cycloisomerisierung. Elektrochemische Oxydation von Nickel(II)‐1‐methyliden‐2,2,7,7,12,12‐hexamethyl‐15‐cyan‐1,19‐secocorinat‐perchlorat. Vorläufige Mitteilung
Authors: Kräutler Bernhard , Pfaltz Andreas , Nordmann René , Hodgson Keith O. , Dunitz Jack D. , Eschenmoser Albert 
Published: December 2004

Experiments on a simulation of the photochemical A/D‐secocorrin → corrin cycloisomerization by redox processes. Electrochemical oxidation of nickel(II)‐1‐methylidene‐2,2,7,7,12,12‐hexamethyl‐15‐cyano‐1,19‐secocorrinate perchlorateCan the act of light excitation in the photochemical A/D‐secocorrin → corrin cycloisomerization be replaced by redox reactions in the dark? Electrochemical oxidation of nickel(II)‐A/D‐secocorrinate 4 in acetonitrile containing a trace of water produces the secocorrinoxide–nickel‐complex 5 (structure determined by X‐ray analysis) in almost quantitative yield. This two‐electron oxidation involves a hydrogen shift from the methylene group C(19) in ring D to the methylidene carbon atom at ring A in the radical cation intermediate. Since the same type of hydrogen shift occurs in the photochemical A/D‐secocorrin → corrin cycloisomerization, a close parallelism in their chemical reactivity seems to exist between electronically excited A/D‐secocorrins and corresponding radical cations. Formation of the corrin complex 2 (M = Ni+) could be achieved (so far only in modest yields) by electrochemical one‐electron oxidation of 4 in acetonitrile/acetanhydride/acetic acid 8:1:1 followed by one‐electron reduction. – The transformation of the oxide nickel complex 5 to the corrinoid complex 10 – a new member in the family of dehydrocorrins – is also recorded.
Abbaureaktionen an 3‐[2′‐(2″‐Dimethylaminoäthyl)‐phenyl]‐isochromanen
Authors: Wiegrebe Wolfgang , Michael Stephan Hans , Fricke Johann , Peter Schlunegger Urs 
Published: December 2004

Degradation of 3‐[2′‐(2′‐Dimethylaminoethyl)‐phenyl]‐isochromanesDegradation of the β‐dimethylaminoethyl sidechain of properly substituted 3‐aryl‐isochromanes produce inter alia the amines 2, the syrenes 3, the aldehyde 5b and the carboxylic acid 4b. The racemates of the amine 15 and the aldehyd 5b were resolved; the chiral center of the menthoxycarbonyl‐hydrazone was eliminated by ester interchange.
Synthèses de produits organofluorés VI Solvolyse de chlorofluorocyclopropanes
Authors: Bessière Yvonne , Schlosser Manfred 
Published: December 2004

Fluoro‐organic Syntheses VI: The Solvolysis of Chlorofluoro‐cyclopropanes2‐Fluoro‐allylic carbocations, generated from 1‐chloro‐1‐fluoro‐cyclopropanes or 2‐fluoro‐allyl p‐toluene‐sulfonates in water or acetic acid, undergo either proton loss or addition of hydroxyl or acetoxyl. In the latter case, an alkyl‐substituted 2‐fluoro‐allyl ion leads predominantly to the more branched product (e.g. 3‐fluoro‐2‐methyl‐3‐buten‐2‐ol) which may be converted into the less branched one (e.g. 2‐fluoro‐3‐methyl‐2‐buten‐2‐ol) through reversible reactions.
The Crystal Structure of (2 R, 7 S, 10 R)‐2,10‐diamino‐5,5,7‐trimethyl‐4,8‐diazaundecanenickel (II) perchlorate
Authors: Stoeckli‐Evans Helen 
Published: December 2004

AbstractThe structure of the title compound, a tricyclic Ni(II) tetra‐amine complex has been determined from analysis of photographic X‐ray data. The crystal system is orthorhombic, space group P212121, with unit cell dimensions a = 9.802, b = 8.998, c = 24.378 Å. The Ni atom is square planar coordinated. The six‐membered chelate ring has a chair conformation. One of the five‐membered chelate rings has a distorted gauche (λ) conformation with the methyl substituent in an equatorial position, the other has an unsymmetrical gauche (δ) conformation with the methyl substituent axial.