bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupling of two phosphaalkynes via a carbonyl group in the addition across a rhrh double bond
Authors: Hitchcock Peter B. , Maah Mohd Jamil , Nixon John F. 
Published: January 2005

AbstractPhosphaalkynes, RCP (R = But, Adamantyl), add across the RhRh double bond of [Rh2Cp(CO)2] to give either [Rh2Cp(μ‐CO)(COPCR)] or [Rh2Cp(CO){PCRC(O)CRP}] depending on the stoichiometry of the reaction (Cp* = η5‐C5Me5). The structures of these complexes have been elucidated by NMR spectroscopy and by a single crystal X‐ray study on [Rh2Cp(CO){PCAdC(O)CPAd}]. Small amounts of the 1,3‐diphosphacyclobutadiene complexes [RhCp*(P2C2R2)] and the trinuclear compound [Rh3Cp(CO)2] are also formed in these reactions. The reactions of RCP with [CoRhCp2*(CO)2] are also described.A preliminary account of part of this work has appeared in J. Chem. Soc., Chem. Commun., 1987, 658.
Products derived from oxidations of 3,4‐dimethyl‐1‐phenylphosphole‐1‐oxide: A 3‐phenyl‐5,6‐dimethyl‐2,3‐oxaphosphabicyclo[2.2.2]octene‐3‐oxide derivative as a precursor of phenyl metaphosphonic anhydride
Authors: Quin Louis D. , Wu Xiao‐Ping 
Published: January 2005

AbstractOxidation of 3,4‐dimethyl‐1‐phenylphosphole with peracids or peroxides gives a relatively stable P‐oxide, which can be used in Diels‐Alder reactions to give derivatives with the 7‐phosphanorbornene framework. Oxygen insertion into a C–P bond of this framework occurs smoothly with m‐ chloroperbenzoic acid (MCPBA) providing derivatives of the 2,3‐oxaphosphabicyclo [2.2.2] octene ring system. The phosphole can be converted to this system in a one‐pot synthesis by reaction with excess MCPBA in the presence of N‐phenylmaleimide as dienophile. The phosphole oxide undergoes mono‐epoxidation with MCPBA. Thermal or photochemical fragmentation of the 2,3‐oxaphosphabicyclo [2.2.2] ocetene is a useful source of the 3‐coordinate species Ph–PO2, a meta‐anhydride of phenylphosphonic acid. This species was trapped successfully with a variety of alcohols.
The syntheses and structures of iron carbonyl adducts of tricoordinated hypervalent phosphorus compounds
Authors: Arduengo Anthony J. , Lattman Michael , Dixon David A. , Calabrese Joseph C. 
Published: January 2005

AbstractThe hypervalent phosphorus compound 3,7‐di‐t‐butyl‐5‐aza‐2,8‐dioxa‐1‐phosphabicyclo[3.3.0]octa‐2,4,6‐triene(ADPO), forms a monosubstituted adduct, ADPO·Fe(CO)4, by direct reaction of 10‐P‐3 ADPO with Fe2(CO)9 or Fe(CO)5, as well as by reaction of 1,1‐dichloro‐3,7‐di‐t‐butyl‐5‐aza‐2,8‐dioxa‐1‐phosphabicyclo[3.3.0]octa‐3, 6‐diene(ADPO·Cl2) with Na2[Fe(CO)4]. The X‐ray crystal structure of ADPO·Fe(CO)4 shows that ADPO is coordinated to the iron through the phosphorus. The phosphorus of the adduct has a tetrahedral 8‐P‐4 geometry in contrast to the planar T‐shaped geometry of uncomplexed 10‐P‐3 ADPO. Ultraviolet photolysis of ADPO·Fe(CO)4 yields the disubstituted species (ADPO)2·e(CO)3 wherein ADPO has dimerized via P–O bond cleavage to form a bidentate (ADPO)2 ligand containing a 10‐membered ring that bridges axial and equatorial positions at the trigonal bipyramidal iron center.
Reactions of a P‐chloro‐iminophosphane with main group nucleophiles: Syntheses and x‐ray crystal structure analyses of two 1,3‐diphosphatetraz‐3‐ene derivatives
Authors: Hein Joachim , Gärtner‐Winkhaus Christiane , Nieger Martin , Niecke Edgar 
Published: January 2005

AbstractThe reactions of chloro(2,4,6‐tri‐tert‐butylphenylimino)phosphane with lithium tris(trimethylsilyl)silanide and lithium diphenylketimide furnish products resulting from the incorporation of a second chloroiminophosphane molecule into the primary substitution product and subsequent nucleophilic displacement of the chlorine ligand. The final products have been characterized by X‐ray structure analyses, which revealed some remarkable features.
Reduction of elemental selenium by samarium diiodide: Selective synthesis of diorganyl selenides and diselenides
Authors: Sekiguchi Masahito , Tanaka Hiromichi , Takami Noriaki , Ogawa Akiya , Ryu Ilhyong , Sonoda Noboru 
Published: January 2005

AbstractThe reduction of elemental selenium by samarium diiodide led to selective formation of selenolate anion species (Se2− and Se22−), the alkylation of which provided dialkyl selenides and diselenides, respectively, in excellent yields.
1λ5,3λ5‐Diphospholium ions
Authors: Schmidpeter Alfred , Mayer Peter , Stocker Johanna , Roberts Kenneth A. , Stang Peter J. 
Published: January 2005

AbstractOne example each is given for the reaction of bromoacetylenes and ethynyl‐phenyliodonium tosylates with bis(diphenyl phosphino)methane. The yellow crystalline 1:1‐addition products are diphospholium salts. They readily and selectively hydrolyze to give 2‐phosphinoylethenyl phosphonium salts.
1,2,4‐Azadiphosphole
Authors: Ionkin A. S. , Ignat'Eva S. N. , Litvinov I. A. , Naumov V. A. , Arbuzov B. A. 
Published: January 2005

Abstracttert‐Butylaminophosphaalkyne 4 is shown to dimerize in alkaline medium to 1‐tert‐butyl‐3‐tert‐butylamino‐1,2,4‐azadiphosphole 1—the first representative of 1,2,4‐azadiphospholes. The structure of 1 has been determined by IR and 31P NMR spectroscopy and by X‐ray crystallography. Compound 1 crystallizes in the triclinic space group P¯1 with a = 10.356(7), b = 11.817(5), c = 11.830(3) Å, α = 88.51(3), β = 78.61(4), γ = 77.05(4)°, V = 1383(1) Å3, Z = 4 (two independent molecules).
The synthesis and thermal property of sodium cyclo‐octaphosphate
Authors: Watanabe Makoto , Honda Tomohiko 
Published: January 2005

AbstractSodium cyclo‐octaphosphate heptahydrate, (NaPO3)8 · 7H2O, has been made by heating lead cyclo‐tetraphosphate at 340°C, dissolving the thermal product in a 3% aqueous solution of tetrasodium ethylene‐diaminetetraacetate, and then crystallizing it by addition of sodium chloride and acetone to the solution. When the cyclo‐octaphosphate was heated up to 400°C, it decomposed to produce phosphates with both shorter and longer chain lengths. A main product at 300° to 350°C was sodium cyclo‐triphosphate, and the thermal product melted at about 630°C.
Molecular and crystal structure of tert‐butylphosphaethyne
Authors: Chernega Alexander N. , Antipin Mikhail Yu. , Struchkov Yuri T. , Meidine Mohamed F. , Nixon John F. 
Published: January 2005

AbstractThe crystal and molecular structure of tert‐butylphosphaethyne, ButCP, liquid at room temperature, has been determined by X‐ray diffraction at 108 K. Main geometrical parameters are as follows: PC 1.542(2), C(sp)–C(sp3) 1.470(3) Å, PCC 179.3(2)°.
Carbapenem antibiotics: Displacement of C‐3 sulfur side chain by another thiol moiety, and quaternization of a weaker pyridine nitrogen over a stronger primary amine (preparation of BMY 40732 and BMY 40886)
Authors: Rao Vanga S. , Rémillard R. , Ménard Marcel 
Published: January 2005

AbstractDisplacement of sulfoxide moiety by a thiol group is shown to be useful in the preparation of 6‐aminoethyl carbapenem derivatives. Also described is a simple strategy to mask a stronger basic primary amine as a nonbasic, nonnucleophilic imine in order to preferentially alkylate (quaternize) a weaker nitrogen of a pyridine in the same molecule. A discussion on the conformational aspects of the β‐lactam‐opened products is also presented.
17O NMR spectroscopy: Proton–oxygen coupling in simple alcohols at natural abundance
Authors: Chandrasekaran Subramanian , Boykin David W. 
Published: January 2005

Abstract17O NMR data are reported for 3‐pentanol (1), cyclopentanol (2), cyclohexanol (3), and cycloheptanol (4). The 17O NMR signals for 1–4 appeared as doublets, shown to arise from proton–oxygen coupling (1JOH = 76 ± 3 Hz) by proton decoupling experiments. The effect of concentration, temperature, and solvent was examined in detail for 2. Proton—oxygen coupling was observed at low concentrations, decreased at lower temperatures, and was sensitive to solvent.
1,2,3‐Selenadiazoles as precursors to cyclopentadienylcobalt dithiolenes and 1,4‐dithiins: molecular structures of bis(cycloocteno)‐1,4‐dithiin and bis(cycloocteno)‐1,4‐diselenin
Authors: Dorrity Michael R. J. , Lavery Ann , Malone John F. , Morley Christopher P. , Vaughan Richard R. 
Published: January 2005

AbstractCycloocteno‐1,2,3‐selenadiazole (1) and cyclopenta‐dienyldicarbonylcobalt (2) react in the presence of an excess of elemental sulfur to yield the dithiolene cyclopentadienyl(1,2‐cyclooctenedithiolato)cobalt (3). Available evidence indicates that this reaction involves the intermediacy of a cobalt–alkyne complex. Compound 3 is the first example of a cyclopentadienylcobalt dithiolene bearing aliphatic substituents. Analogous reactions performed using only catalytic quantities of 2 provide high‐yield syntheses of bis(cycloocteno)‐1,4‐dithiin (6) and bis(cycloocteno)‐1,4‐diselenin (7), whose structures have been determined by X‐ray diffraction.
Phosphorylated derivatives of 1‐morpholinocyclohexene and cyclohexanone
Authors: Tolmachev Andrew A. , Kostyuk Alexander N. , Kozlov Ernest S. , Chernega Alexander N. , Pinchuk Alexander M. 
Published: January 2005

AbstractPhosphorylation of a relatively simple enamine with phosphorus (III) halides was first exemplified by the behavior of 1‐morpholinocyclohexene. Novel types of functionalized P(III) derivatives have now been obtained and studied. The hydrolysis of (2‐morpholino‐1‐cyclohexenyl) tetraethyldiamidophosphazidoarenes was found to be accompanied by the migration of the triazene group from the phosphorus atom to the carbon atom of the cyclohexene ring.
MNDO calculations on boron–nitrogen derivatives of nonbenzenoid aromatics: I. The two fully boron–nitrogen‐alternating isomers of “inorganic azulene”
Authors: McFarland Jennifer D. , Welk Natalie A. (Jackson) , Zoellner Robert W. 
Published: January 2005

AbstractModified neglect of diatomic overlap (MNDO) calculations have been used to investigate the ground state properties of the two fully boron‐nitrogen‐alternating isomers of “inorganic azulene”: 1,3,4,6,8‐pentaaza‐2,3a, 5,7, 8a‐pentaboraazulene (1, 1,3,4,6,8‐PAPBAZ) and 2,3a,5,7,8a‐pentaaza‐1,3,4,6,8‐pentaboraazulene (2, 2,3a,5,7,8a‐PAPBAZ). Both molecules optimize to planar structures, have exothermic heats of formation (−194.4 kcal/mol and −161.4 kcal/mol, respectively), and exhibit some bond delocalization. The relationship of these two PAPBAZ isomers to their organic parent molecule, azulene, is discussed.
Synthesis of carboranes containing nucleoside bases
Authors: Yamamoto Yoshinori , Seko Toshiya , Nakamura Hiroyuki , Nemoto Hisao 
Published: January 2005

AbstractThe carboranes containing uridine derivatives (9a,b,c), and purine base (8) were prepared by the reaction of decaborane with the corresponding acetylene precursors (3a, 3b, 2c and 5b, respectively).
Facile and convenient synthesis of B‐amino‐9‐borabicyclo[3.3.1]nonanes. Aminoboration of lsocyanates
Authors: Singaram Bakthan 
Published: January 2005

AbstractThe reaction of 9‐borabicyclo[3.3.1]nonane (9‐BBN) with aliphatic and aromatic primary and secondary amines in tetrahydrofuran (THF) at 65°C proceeds rapidly and quantitatively with evolution of hydrogen and the formation of the corresponding B‐amino‐9‐borabicyclo[3.3.1] nonane (B‐amino‐9‐BBN). Simple evaporation of THF from the reaction mixture gives the B‐amino‐9‐BBN derivatives in high yield and purity. These B‐amino‐9‐BBN derivatives are reactive towards alkyl and aryl isocyanates. Consequently, the aminoboration of various isocyanates has been studied using B‐phenylamino‐9‐BBN. Thus, two equivalents of isocyanates react with one equivalent of B‐phenylamino‐9‐BBN to afford, following the hydrolysis of the intermediate with ethanolamine, N, N'‐disubstituted‐N ‐(phenylamido)‐ureas in excellent yields. A plausible mechanism for this aminoboration reaction of isocyanates is also presented.
Hindered organoboron groups in organic synthesis. 17 [1]. Synthesis of 2,4,6‐triisopropylphenylborane (TripBH2)2, a useful alternative to thexylborane
Authors: Pelter Andrew , Smith Keith , Buss Dieter , Jin Zhao 
Published: January 2005

Abstract2,4,6‐Triisopropylphenylborane (tripylborane, TripBH2) resembles thexylborane in having a single, bulky organic group attached to boron, but the group is aromatic rather than aliphatic. The compound has been synthesized by two alternative routes, one involving direct reduction of dimethoxytripylborane and the other involving redistribution between ditripylborane and borane. It is a solid which is considerably more stable than thexylborane.
Halogenolysis of Se‐methyl phosphinoselenoates
Authors: Krawiecka B. 
Published: January 2005

AbstractThe reaction of the title phosphinoselenolates with sulfuryl chloride and halogens was investigated stereochemically and spectroscopically (31P NMR at variable temperatures). Differences were observed in the reaction course when compared to the behavior of sulfur analogs towards the same reagents. The good donor character of the selenium atom and the leaving ability of the –Se+(R)X group explain well the results of the investigation.
Molecular and electronic structure of selenium and tellurium tetrahalides
Authors: Novak Igor 
Published: January 2005

AbstractMolecular and electronic structures of MX4 (M = Se, Te: X = F, Cl) were studied by the ab initio method with extended basis sets. The study is aimed at supplementing very scarce experimental information about these molecules. The results indicate that all molecules favour distorted disphenoidal geometries (C2v point group) in preference to a C4v geometry. A possibly interesting phenomenon of energy stabilisation by having bonds of different polarities within the same molecule has been observed in SeCl4 and TeCl4.
Synthesis and characterization of functional cyclopentasilanes
Authors: Jenkner P. K. , Spielberger A. , Hengge E. 
Published: January 2005

AbstractCleavage of the exocyclic Si‐Si‐bond of phenyldimethysilylnonamethylcyclopentasilane3by sodium ethoxide followed by chlorination with acetyl chloride leads to the monofunctional chlorononamethylcyclopentasilane5. Subsequent hydration gives hydrononamethylcyclopentasilane6, which can be easily converted to the corresponding bromo and iodo derivatives7,8. Fluorononamethylcyclopentasilane can be prepared upon treatment of7with ZnF2. A different but convenient synthetic pathway to the halononamethylcyclopentasilanes has also been achieved employing the corresponding trifluoromethanesulfonic acid ester11. The halogen derivatives—as expected—show a strong influence on the physical properties of the compounds.These functionalized cyclopentasilanes may serve as useful synthetic tools in building larger oligosilane ring systems.
Studies on organophosphorus compounds 56. New reaction of dialkyl phosphites with 2‐nitrostyrene derivatives—a facile route to N‐hydroxy‐3‐indole phosphonates and indol‐2‐one phosponates
Authors: Wang Guohong , Yuan Chengye 
Published: January 2005

AbstractReaction of a dialkyl phosphite with a 2‐nitrostyrene in the presence of triethylamine, trimethylsilyl chloride, and hexamethyldisilazane provides a one‐pot procedure for the synthesis of an N‐hydroxy‐indole‐3‐phosphonate and an indole‐2‐one‐3‐phosphonate besides the normal addition product, a 1‐aryl‐2‐ni‐troalkylphosphonate. Such new indole derivatives are difficult to prepare by conventional methods. The ratios of reactant to silylating agent and base were found to have significant influence on the product composition. The mechanism of formation of these het‐erocyclic products is discussed.
Synthesis and reactions of optically active phosphine‐boranes
Authors: Imamoto Tsuneo , Oshiki Toshiyuki , Onozawa Takashi , Matsuo Masatoshi , Hikosaka Takaaki , Yanagawa Masao 
Published: January 2005

AbstractSynthesis and reactions of optically active phosphine‐boranes have been investigated. Optically active secondary phosphine‐boranes, (Sp)‐and (Rp)‐menthyloxyphenylphosphine‐boranes, and (S)‐methylphenylphosphine‐borane underwent palla‐dium(0)‐catalyzed electrophilic arylation with o‐, m‐, or p‐iodoanisole. The stereochemistry of this arylation was largely dependent on the solvent and the base used. The reaction in acetonitrile proceeded with almost complete retention of configuration at the chiral phosphorus, whereas inversion of configuration was observed in ethereal solvents or toluene. The phosphorus‐oxygen bond of (Rp)‐menthyloxy (methyl) phenylphosphine‐borane and (SP)‐menthy‐loxy(o‐methoxyphenyl)phenylphosphine‐boranewas reductively cleaved at −78°C by lithium naphtha‐lenide or Li/NH3 with virtually net retention of configuration at phosphorus, providing secondary or tertiary phosphine‐boranes in excellent yields. New synthetic routes to optically pure C2‐symmetric bisphosphine‐boranes possessing chirality at phosphorus have been developed on the basis of these stereochemical studies.
Reaction of phenyliodonium ylides of β‐dicarbonyl compounds with allylic sulfides and selenides
Authors: Yang Rui‐Yang , Dai Li‐Xin , Ma Ru‐Jian 
Published: January 2005

AbstractAn efficient and mild reaction for introducing an allylic moiety and an alkylthio‐ or alkylseleno‐group onto the α‐carbon of β‐dicarbonyl compounds in one step by tandem transylidation and [2,3]‐sigmatropic rearrangement is described.
Syntheses and characterization of pentacoordinate organo‐tin(IV) complexes
Authors: Wang Ji‐Tao , Zhang Yun‐Wen , Xu Yu‐Ming , Wang Zhi‐Wen 
Published: January 2005

AbstractTen novel pentacoordinate organo‐tin complexes were prepared and characterized. Single crystal structure determinations by X‐ray diffraction and also chemical investigations were made.
The reaction of dipolarophiles with arenealdoxime dehydrodimer
Authors: Wei Xudong , Zhang Zhuangyu , Li Jiaming , Hu Hongwen 
Published: January 2005

AbstractThe reactions of dipolarophiles with arenealdoxime dehydrodimers 1 have been studied. The reaction products depend upon the dipolarophile used. The reaction of 1 with styrene afford linear adducts. Active dipolarophiles, such as methyl acrylate and dimethyl acetylenedicarboxylate, lead to 1,3‐cycloaddition products. The possible mechanisms for both cases are discussed.
Crystal and molecular structure of 5,5‐dimethyl‐1,3‐dithian‐2‐ylcarboxylic acid. Is the axial conformer stabilized by hydrogen bonds?
Authors: Mikołajczyk Marian , Graczyk Piotr P. , Wieczorek Michał W. , Błaszczyk Jarosław 
Published: January 2005

AbstractThe crystal structure of the title compound (3) was determined by the X‐ray diffraction technique from diffractometer intensity measurements: C7H12O2S2, monoclinic space group P21/c, a = 12.644(1) Å, b = 6.102(1) Å, c = 12.920(2) Å, B = 110.78(1)°, 2193 reflections, and R = 0.043. The molecule of (3) adopts a chair conformation in which the carboxyl group occupies an axial position. The contacts between the carbonyl oxygen and axial hydrogens at C(4) and C(6) of 2.564 and 2.697 Å are smaller than the sum of van der Waals radii of this oxygen and hydrogen atoms, indicating a possibility of intramolecular CO· ·HC hydrogen bond formation. The acid 3 forms also dimeric structures via intermolecular hydrogen bonds with contact between hydroxyl hydrogen and carbonyl oxygen of 1.439 Å and OH· · ·O angle of 176.2°.
Insertion of CS2 into CuS bonds (II). Preparation and crystal structure of insertion product with CS2 [Cu6(S2CSC6H2Pri3‐2,4,6)4(SC6H2Pri3‐2,4,6)2] · 2CHCl3 · 4CH3OH
Authors: Tang Kaluo , Wu Dedong , Jin Xianglin , Tang Youqi 
Published: January 2005

AbstractComplex [Cu(SC6H2Pri 3‐2,4,6)]8 (1) reacts with a small amount of CS2 to give red crystals [Cu6(S2CSC6H2Pri3‐2,4,6)4(SC6H2Pri3‐2,4,6)2] · 2CHCl3 · 4CH3OH (2), and CS2 is inserted into two‐thirds of the CuS bonds of complex (1). The unusual structure of complex (2) consists of six copper atoms linked through arenethiolate (RS−) and aryl trithiocarbonate (RSCS2−) ligands, exhibiting a number of interesting features. Crystal data: triclinic, space group P1, a = 14.298(4), b = 14.282(5), c = 17.745(7)Å, α = 109.92(3), β = 111.88(3), γ = 90.42(2)°, Z = 1, R = 7.83%, for 4118 observed reflections.
Occurrence of ligand coupling in the reaction of the 2‐thienyl sulfoxides with organometallic compounds
Authors: Oae Shigeru , Inubushi Yoichi , Yoshihara Masakuni 
Published: January 2005

AbstractTreatment of 2‐pyridyl 2‐thienyl sulfoxide with 2‐thienyllithium was found to give both 2‐(2‐pyridyl)thiophene 2 and 2,5‐(di‐2‐pyridyl)thiophene 3. The reaction between 2‐thienyllithium and thionyl chloride was found to give 2,2′‐bithienyl 8, a coupling product, which is also formed by the reaction between di‐2‐thienyl sulfoxide 7 and 2‐thienyllithium.
Oxygen‐18 labeling of cyclic and acyclic sulfinate esters
Authors: Okuyama Tadashi , Senda Koji , Takano Hitomichi , Ando Noriyuki , Ohnishi Kazunori , Fueno Takayuki 
Published: January 2005

AbstractBoth cyclic and acyclic sulfinate esters were labeled with 18O at the sulfinyl oxygen by acid‐catalyzed isotope exchange with H218O or alkaline hydrolysis in H218O followed by re‐esterification. Long‐range 18O isotope effects on the 13C NMR chemical shifts were observed.
Facile reductive deamination of arylamines using a new arenesulfonyl nitrite
Authors: Shin Hyun Ho , Park Young Jun , Kim Yong Hae 
Published: January 2005

AbstractArenesulfonic acids were found to react with dinitrogen tetraoxide at −40°C in tetrahydrofuran to form arenesulfonyl nitrites which showed excellent diazotizing ability for the reductive deaminations of arylamines to arenes in the presence of anhydrous copper(II) halides as catalysts.
Structural studies of tris(dialkylamino) sulfonium (TAS) fluorosilicates
Authors: Dixon David A. , Farnham William B. , Heilemann W. , Mews R. , Noltemeyer M. 
Published: January 2005

AbstractThe crystal structures of two pentavalent silicon anions are discussed. The structure of [SiMe3F2]− 1 shows a trigonal bipyramidal structure with the fluorines in apical positions. The SiF bond distances are the longest known of this type. The crystal structure of fluorosilicate 2 (1,1‐diphenyl‐1‐fluoro‐3,3‐bis[trifluoromethyl]‐1,3‐dihydro‐2,1‐benzoxasilole[ion 1‐]) is distorted toward a rectangular structure along the Berry pseudorotation coordinate. The lone SiF bond distance in 2 is much shorter than that in 1. The ab initio calculations on a variety of pentavalent fluorinated silicon anions are reported, and good agreement with the experimental data are found. Fluoride affinities for the fluorosilanes are reported and are in reasonable agreement with the experimental values where known. The fluoride affinity of the tetra‐coordinated species is related to the length of the SiF bond in the pentavalent anion.
The photochemical properties of the mono‐and dithioimide derivatives of (E,E)‐dibenzylidene‐N‐phenylsuccinimide
Authors: Davidse P. Adriaan , Dillen Jan L. M. 
Published: January 2005

AbstractNovel (E,E)‐dibenzylidene‐N‐phenyl succinimide thioimide 1b and dithioimide 1c derivatives of the photochromic fulgimide 1a were synthesized. The thioimide 1b and dithioimide 1c derivatives were found to undergo isomerization as the main photoreaction when irradiated in a variety of organic solvents, as opposed to the reversible electrocyclic ring closure/opening reactions in the case of the fulgimide 1a. The X‐ray crystal structures of 1b and 1c were determined, and the influence of the thiocarbonyl groups on the structural parameters were investigated in comparison to the crystal structure of 1a. The 1H and 13C NMR spectra were recorded for all three compounds 1a, 1b, and 1c and are discussed in terms of their structural and electronic variations, as is the effect on the photochemical behavior. The twisting of the N‐phenyl ring was found to be a consequence of intramolecular steric interactions and not of intermolecular packing forces. This was substantiated by a series of semiempirical (AMI) calculations. The C(thiocarbonyl) was found to be highly deshielded compared to the corresponding C(carbonyl) carbon atom, and the deshielding effect of the thiocarbonyl group was evident throughout the whole thiocinnamic moiety. Crystal data for monothioimide 1b: spacegroup P21/c with a = 8.794(2) Å, b = 9.623(1) Å, c = 22.182(5) Å, β = 91.45(2)°, Rw = 0.038, and R = 0.067. Dithioimide 1c: spacegroup Pnna with a = 9.411(2) Å, b = 17.304(2) Å, c = 13.574(2) Å, Rw = 0.055, and R = 0.077.