bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyrromethene–BF2 complexes as laser dyes: 2
Authors: Boyer Joseph H. , Haag Anthony M. , Sathyamoorthi Govindarao , Soong Mou‐Ling , Thangaraj Kannappan , Pavlopoulos Theodore G. 
Published: January 2005

AbstractPyrromethene–BF2 complexes (P–BF2) 7 were obtained from α‐unsubstituted pyrroles 5 by acylation and condensation to give intermediate pyrromethene hydrohalides 6 followed by treatment with boron trifluoride etherate. Conversion of ethyl α‐pyrrolecarboxylates 4 to α‐unsubstituted pyrroles 5 was brought about by thermolysis in phosphoric acid at 160°C, or by saponification followed by decarboxylation in ethanolamine at 180°C, or as unisolated intermediates in the conversion of esters 4 to pyrromethene hydrobromides 6 by heating in a mixture of formic and hydrobromic acids. Addition of hydrogen cyanide followed by dehydrogenation by treatment with bromine converted 3,5,3′,5′‐tetramethyl‐4,4′‐diethylpyrromethene hydrobromide 9 to 3,5,‐3′,5′‐tetramethyl‐4,4′‐diethyl‐6‐cyanopyrromethene hydrobromide 6bb, confirmed by the further conversion to 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐cyanopyrromethene–BF2 complex 7bb on treatment with boron trifluoride etherate.An alternation effect in the relative efficiency (RE) of laser activity in 1,3,5,7,8‐pentamethyl‐2,6‐di‐n‐alkylpyrromethene–BF2 dyes depended on the number of methylene units in the n‐alkyl substituent, ‐(CH2)nH, to give RE ≥ 100 when n = 0,2,4 and RE 65, 85 when n = 1,3. (The RE 100 was arbitrarily assigned to the dye rhodamine 6G). The absence of fluorescence and laser activity in 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐isopropylpyrromethene–BF2 complex 7p and a markedly diminished fluorescence quantum yield (Φ 0.23) and lack of laser activity in 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐cyclohexylpyrromethene–BF2 complex 7q were attributed to molecular nonplanarity brought about by the steric interference between each of the two bulky 8‐substituents with the 1,7‐dimethyl substituents. An atypically low RE 20 for a peralkylated dye without steric interference was observed for 1,2,6,7‐bistrimethylene‐3,5,8‐trimethylpyrromethene–BF2 complex 7j. Comparisons with peralkylated dyes revealed a major reduction in RE 0–40 for the six dyes 7u–z lacking substitution at the 8‐position.Low laser activity RE was brought about by functional group (polar) substitution in the 2,6‐diphenyl derivative 7I, RE 20, and the 2,6‐diacetamido derivative 7m, RE 5, of 1,3,5,7,8‐pentamethylpyrromethene–BF2 complex (PMP–BF2) 7a and in 1,7‐dimethoxy‐2,3,5,6,8‐pentamethylpyrromethene–BF2 complex 7n, RE 30. Diethyl 1,3,5,7‐tetramethyl‐8‐cyanopyrromethene‐2,6‐dicarboxylate–BF2 complex, 7aa, and 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐cyanopyrromethene–BF2 complex, 7bb, offered examples of P–BF2 dyes with electron withdrawing substituents at the 8‐position. The dye 7aa, λlas 617 nm, showed nearly twice the power efficiency that was obtained from rhodamine B, λlas 611 nm.
Synthesis and stability of 2,4,6‐trinitrobenzylamine
Authors: Sitzmann Michael E. , Adolph Horst G. 
Published: January 2005

Abstract2,4,6‐Trinitrobenzylamine was synthesized via 2,4,6‐trinitrophenylacetic acid and 2,4,6‐trinitrobenzyl isocyanate. The title compound decomposes at room temperature but forms a stable hydrochloride and acetyl derivative.
Synthesis of some sulfur‐containing spiro‐pyrimidinetriones, pyrazolidinediones, and isoxazolidinediones
Authors: Reddy D. Bhaskar , Padmavathi V. , Seenaiah B. , Padmaja A. 
Published: January 2005

AbstractNovel sulfur‐containing spiro compounds such as 7,11‐diaryl‐9‐thia‐2,4‐diazaspiro [5,5] undecane‐1,3,5‐trione 9,9‐dioxides (2), 6,10‐diaryl‐8‐thia‐2,3‐diazas‐piro[4,5]decane‐1,4‐dione‐8,8‐dioxides (3) and 6,10‐diaryl‐2‐oxo‐8‐thia‐3‐azaspiro [4,5] decane‐1,4‐dione‐8,8‐dioxides (5) have been prepared by the condensation of 4‐dimethoxycarbonyl/diethoxycarbonyl‐3,5‐diaryl‐1‐thiane 1,1‐dioxides (1) with urea, hydrazine hydrate, and hydroxylamine hydrochloride, respectively. The N‐substituted derivatives (4 and 6) of 3 and 5 have also been prepared by acylation and nitrosation. The structures of 2, 3, and 5 were established by IR, 1H NMR, and 13C NMR spectral studies, respectively.
Reduction of O‐methyl oxime ethers of conjugated cyclohexenones with aluminum hydride
Authors: Zaidlewicz Marek , Uzarewicz Ireneusz G. 
Published: January 2005

AbstractThe reduction of representative O‐methyl oxime ethers 1–4 with aluminum hydride in tetrahydrofuran yielded allylic amines and saturated aziridines as the main products. The stereochemical course of the reduction to aziridines depends on the oxime ether configuration. Thus, E–3, E–4 and Z–3, Z–4 gave 15, 16 and 21, 22, respectively, with high stereoselectivity. Higher reactivity of Z than E isomers was utilized for the preparation of pure E isomers of oxime ethers from E, Z mixtures.
Crystal and molecular structures and the absolute configuration of O,Se‐dimethyl‐N‐(1‐phenylethyl)phosphoramidoselenoates
Authors: Wieczorek Michał W. , Błaszczyk Jarosław , Krzyżanowska Bożenna 
Published: January 2005

AbstractThe structural investigation of two enantiomers of the phosphoroorganic selenium‐containing compound [(+)C10H16NO2PSe (1) and (−)C10H16NO2PSe (1′)] was carried out. The absolute configuration at the P and C3 atoms was found to be R for compound 1 and, respectively, S for compound 1′.
The reaction of pentasubstituted 3‐hydroxy‐1,2‐dioxolanes (hemiperketals) with trivalent phosphorus compounds: Synthesis of β‐hydroxy ketones
Authors: Baumstark Alfons L. , Vasquez Pedro C. , Chen Yaxiong 
Published: January 2005

AbstractThe reaction of a series of 4,4‐dimethyl‐3,5,5‐(R3, R2, R1)‐3‐hydroxy‐1,2‐dioxolanes 1a–d [1a (R1 = R2 = R3 = Me); 1b (R1 = R2 = Me, R3 = Ph); 1c (R1 = Ph, R2 = R3 = Me); 1d (R1 = R3 = Ph, R2 = Me)] with trimethyl phosphite or triphenylphosphine produced the β‐hydroxy ketones, 2a–d [(R1R2C(OH)CMe2‐COR3)], and the corresponding phosphoryl compounds in high yield. The reactions were slow (∼24 hours), requiring excess of the trivalent phosphorus compounds for optimum results. The reaction was found to be of the second order overall, first order in peroxide and in phosphorus reagent. Triphenylphosphine was found to be more reactive than trimethyl phosphite. Formal substitution of a phenyl group for a methyl group on the hemiperketals yielded a reduction of reactivity of ∼2.4‐fold at the 3‐position but an increase in reactivity (∼1.5‐fold) at the 5‐position. The rate constants for tautomerization of 1c in benzene were determined. The activitation parameters for reaction of 1c with triphenylphosphine in benzened6 were determined [ΔH‡ = 15.0 ± 1.5 kcal/mol; ΔS‡ = −21.7 eu; ΔG‡ = 21.7 kcal/mol; k34° = 2.4 × 10−3 M−1 s−1]. The data are consistent with direct insertion of the phosphorus compounds into the peroxide bond to yield phosphorane intermediates. Rapid intramolecular hydrolysis of the intermediates would produce the β‐hydroxy ketones and phosphoryl compounds.
Photochemical fragmentation of the 2‐phosphabicyclo[2.2.2]octa‐5,7‐diene ring system as a versatile method for generating 3‐coordinate methylene phosphine oxides and sulfides
Authors: Quin Louis D. , Tang Jian‐Sheng , Quin Gyöngyi S. , Keglevich György 
Published: January 2005

Abstract1,6‐Dihydrophosphinine 1‐oxides with 4‐chloro‐3(or 5)‐methyl substituents give cycloadducts with dimethyl acetylenedicarboxylate having the 2‐phosphabicyclo[2.2.2]octa‐5,7‐diene ring system that can be fragmented easily on irradiation with ultraviolet light (254 nm). The phosphorus‐containing bridge is released as a derivative of the 3‐coordinate methylene phosphine oxide species, RP(O)CH2. This species is too reactive to observe but is readily trapped by an addition reaction with alcohols to give phosphinates (R = alkyl or aryl) or phosphonates (R = O‐alkyl). These experiments constitute the first demonstration of the existence of ROP(O)CH2. Phosphoryl oxygen in the cycloadducts has been replaced by sulfur, and these sulfides fragment smoothly on irradiation. The 3‐coordinate species PhP(S)CH2 has been generated by other workers, but the species ROP(S)CH2 was generated here for the first time. The power of the bicyclic fragmentation route for the generation of a variety of 3‐coordinate P‐methylene derivatives is made evident by this study.
Dihalo derivatives of 3‐coordinate hypervalent phosphorus compounds
Authors: Arduengo Anthony J. , Breker Johannes , Davidson Fredric , Kline Michael 
Published: January 2005

AbstractThe preparation of 1,1‐difluoro‐3,7‐di‐tert‐butyl‐2,8‐dioxa‐1‐phosphabicyclo[3.3.0]octa‐3,6‐diene (Dit‐BuADPO·F2)from hexafluoropropylene oxide (HFPO) and 3,7‐di‐tert‐butyl‐2,8‐dioxa‐1‐phosphabicyclo[3.3.0]octa‐2,4,6‐triene (DitBuADPO) is described. The solid state structure of DitBuADPO·F2 shows an unusual square pyramidal geometry. The structural and spectroscopic properties of DitBuADPO·F2 are compared with other oxidized derivatives of DitBuADPO that contain 5‐coordinate phosphorus.
Selective formation of trichloro(2‐oxoalkyl)telluriums and dichlorobis(2‐oxoalkyl)telluriums from tellurium tetrachloride and enol silyl ethers
Authors: Han Li‐Biao , Kambe Nobuaki , Ikura Masahiro , Ryu Ilhyong , Sonoda Noboru 
Published: January 2005

AbstractThe reactions of TeCl4 with 1 or 2 equivalents of enol silyl ethers yielded trichloro(2‐oxoalkyl)telluriums or dichlorobis(2‐oxoalkyl)telluriums, respectively, in high yields. Stepwise addition of two different enol silyl ethers to TeCl4 in CH2Cl2 led to the selective formation of unsymmetrical dichlorobis(2‐oxoalkyl)telluriums.
The nature of Krause's adducts: The structure of the 1:1 adduct of triphenylborane with sodium metal
Authors: Eisch John J. , Dluzniewski Tomasz , Behrooz Mohammad 
Published: January 2005

AbstractTriphenylborane (7) undergoes reductive dimerization with sodium metal in diethyl ether solution to form a yellow solid (3) having the empirical composition Ph3B· Na· (C2H5)2O. By 1H NMR spectroscopy, 3 has now been shown to have the structure depicted. By the
chemical structure image
action of heat or strongly donor ethers, 3 rearranges into 6, whose structure was likewise determined by 1H and 11B NMR spectroscopy and by deuteriodeboronation with DOAc. Prolonged reaction of sodium metal with 7 or with diphenylboron chloride (8) in DME leads to biphenyl precursors, sodium tetraphenylborate (9), and sodium phenylborohydrides. All these results can be reconciled by the formation of the radical–anion 10 from 7 and its subsequent coupling or fragmentation. The coupling of 10 to form 3 and the rearrangement of 3 to yield 6 shows that there is a striking parallel in behavior between the isoelectronic (Ph3B·)− and the triphenylmethyl radical (Ph3C·). In this light, the solution of the “hexaphenylethane riddle” is also applicable to the solution of the “hexaphenyldiborate dianion riddle,” which was posed by the discovery of Krause's adduct over 68 years ago.
α‐Trifluoromethyl substituted α‐aminoacids and α‐hydroxyacids with organometallic moieties in the side chain [1,2]
Authors: Sewald Norbert , Gaa Karl , Burger Klaus 
Published: January 2005

AbstractSeveral strategies for the synthesis of α‐trifluoromethyl substituted α‐aminoacids and α‐hydroxyacids with organometallic moieties in the side chain are described. The preparative potential of organometallic substituents (organosilicon, organotin, and organocobalt moieties) offers a convenient methodology for the synthesis of highly functionalized α‐aminoacid and α‐hydroxyacid derivatives.
X‐Ray crystallographic study of a 1,3,2‐dioxaphosphorinane dimer containing five‐coordinated phosphorus in the 12‐membered ring
Authors: Huang Yande , Sopchik Alan E. , Arif Atta M. , Bentrude Wesley G. 
Published: January 2005

AbstractAttempted preparation of phosphorane 9 with a 1,3,2‐dioxaphosphorinane ring attached diequatorially to phosphorus led to a mixture of products from which was isolated 12‐membered ring phosphorane 10, formally the dimer of 9, in low yield (22%). An X‐ray crystal structure of 10 revealed a highly symmetrical molecule with trigonal bipyramidal geometry at both phosphorus atoms. The 12‐membered ring is attached to phosphorus diequatorially. The ring is strongly puckered about phosphorus with an equatorial O‐P‐O angle of 110°. The chemical shift equivalence of the CH2O resonances in the 1H NMR spectrum of 10 shows the 12‐membered ring to be highly mobile at ambient probe temperature. At −89°C, these resonances are fully decoalesced. The value of ΔG‡ for the process that averages these peaks was found to be 10.1 kcal/mol at coalescence (−42.0°C).
Coordinating ability of the heterocycles 1,3‐dithia‐2‐arsa‐ and stiba‐cyclopentanes. Part III. Dithioacid and dithiocarbamate complexes containing a free functional group. Crystal structure of 2‐pyrrolidonedithiocarbamate of 1,3‐dithia‐arsa‐cyclopentane
Authors: Cea‐Olivares Raymundo , Toscano Rubén Alfredo , López Marcela , García Patricia 
Published: January 2005

AbstractThree 1,1‐dithioacids containing an additional functional group, 2‐pyrrolidone‐1‐carbodithioic acid, 2‐hydroxycyclopentene‐1‐carbodithioic acid, and 2‐pyrrolidone‐1,3‐bis(carbodithioic) acid, were reacted with the Group 15 heterocycles 2‐chloro‐1,3‐dithia‐2‐arsa‐ and stiba‐cyclopentanes (CIMS2C2H4; M = As, Sb). The dithiocomplexes obtained were characterized by spectroscopic methods and elemental analyses. The X‐ray structure determination of the 2‐pyrrolidonedithiocarbamate of 1,3‐dithia‐arsacyclopentane shows a monodentate behavior of the dithiocarbamate entity and the absence of participation of the carbonyl oxygen in the coordination.
A[1,2,3]benzothiadiphospholo [3,2‐b]‐[1,2,3] benzothiadiphosphole as a further product from the reaction of aryl methyl thioethers with PCl3 and AlCl3
Authors: Baccolini Graziano , Mosticchio Carmine Antonio , Mezzina Elisabetta , Rizzoli Corrado , Sgarabotto Paolo 
Published: January 2005

AbstractThe title compound 2b was obtained as a minor product in the reaction between a thioanisole and PCl3/AlCl3. The crystal and molecular structure has been determined by single crystal X‐ray techniques. The compound crystallizes in the space group P 21/c, with α = 9.004(2), b = 13.416(3), c = 11.662(3) Å, and β = 93.1 (1)°. The molecule adoptes a “butterfly” arrangement.
1,4,7,8‐Triazaborabicyclooctanes—first examples of new boron heterocycles [1,2]
Authors: Tapia‐Benavides Antonio Rafael , Contreras Rosalinda 
Published: January 2005

AbstractThe first examples of 1,7,1,4,7,8‐dialkyltriazaborabicyclo[3.3.0]octanes 1–3 [R = isopropyl (1), R = 1‐phenylbenzyl (2), R = 1‐methylbenzyl (3)] are reported. The bulky substituents prevent dimerization and make the syntheses feasible. The structures and conformations of the new compounds were studied by NMR spectroscopy. A chiral bicycle 3 (R,R) was also prepared.
Phosphorylated indolizines
Authors: Tolmachev Andrew A. , Yurchenko Aleksander A. , Kozlov Ernest S. , Shulezhko Vasiliy A. , Pinchuk Aleksander M. 
Published: January 2005

AbstractPreparative methods of synthesis of 1‐ and 3‐phosphino‐indolizines by interaction between 2‐substituted indolizines with phosphorus(III) halogenides in the presence of bases have been developed. It was found that originally this reaction results in the formation of 1‐phosphino‐indolizines which then undergo izomerization into 3‐phosphino isomers. One, two, or three indolizine substituents can be consecutively attached to the phosphorus atom. New methods of syntheses of 1,3‐diphosphino‐indolizines have been developed.
Structural evidence for Pπ‐Pπ conjugation in aminosubstituted phosphaalkynes
Authors: Chernega Alexander N. , Koidan Georg N. , Marchenko Anatoly P. , Korkin Anatoly A. 
Published: January 2005

AbstractThe molecular structure of 2,2,6,6‐tetramethylpiperidinophosphaalkyne was determined by the X‐ray structural method. The main geometrical parameters are as follows: PC 1.559(2), NC(sp) 1.316(2) Å, PCN 178.9(1)°, with an almost planar trigonal bond configuration for the N atom and the chair conformation of the piperidine ring. Structural evidence for the nitrogen lone pair conjugation with the π‐system of the triple bond was found to be different in phosphaalkynes PC‐NR2 and nitriles NCNR2. Quantum‐chemical ab initio calculations (HF/631G*) showed that this is caused by a different character of polarization of the PC and NC triple bonds.
Crystal structure and vibrational spectrum of copper mercury ortho‐thiophosphate CuHgPS4
Authors: Menzel Frank , Brockner Wolfgang , Carrillo‐Cabrera Wilder 
Published: January 2005

AbstractThe compound CuHgPS4 crystallizes in the orthorhombic system, space group Pna21 (No. 33), Z = 4, with lattice parameters a = 12.660(3), b = 7.3498(7), c = 6.0943(4) Å, and δcalc = 4.96 g/cm3. The title compound is stable in air and moisture and behaves as a semiconductor. The crystal structure consists of discrete tetrahedral PS43‐ anions joined together by Cu+ and Hg2+ cations. The arrangement of the sulfur atoms is approximately hexagonal close‐packed in which P, Cu, and Hg occupy tetrahedral sites. The PS4, HgS4, and CuS4 tetrahedra are slightly distorted with mean distances d(P‐S) = 2.055, d(Hg‐S) = 2.524, and d(CuS) = 2.320 Å, and 8% of the Hg atoms were found to be disordered, occupying interstitial tetrahedral sites. The title compound is isotypic to AgZnPS4 and can be considered to be a defect structure of Enargite (Cu3AsS4), which is a substitution derivative of the Wurtzite (ZnS) structure. The CuHgPS4 vibrational spectrum has been recorded. The internal modes experimentally observed are in accord with the factor group prediction. A tentative assignment of the vibrational frequencies is proposed.
Crystal and molecular structure and the absolute configuration of N‐phenyl‐N′‐(1‐phenylethyl)methanephosphonodiamidate
Authors: Wieczorek Michał W. , Błaszczyk Jarosław , Krzyżanowska Bożenna 
Published: January 2005

AbstractThe structural investigation of the product of the reaction of methanephosphonodichloridate with R(+)‐1‐phenylethylamine and aniline in the presence of triethylamine [3] was performed. The obtained compound C15H19N2OP (1) crystallizes in monoclinic system, space group P21 with a = 10.466(1) Å, b = 6.984(3) Å, c = 10.471(2) Å, β = 95.43(1)°, V = 762.0(9) Å3. Z = 2, and R = 0.037. The absolute configuration at the P and C8 atoms was determined by means of X‐ray crystallography as Rp and Rc8, respectively.
Reactions of triarylphosphines with organolithium reagents. Formation of biaryls
Authors: Uchida Yuzuru , Kawai Masaaki , Masauji Haruo , Oae Shigeru 
Published: January 2005

AbstractTriarylphosphines bearing 2‐pyridyl or 2‐benzothiazyl groups react with organolithium reagents at −78°C in THF to afford both coupling products and ligand exchanged triarylphosphines. The ligand coupling and ligand exchange are considered to take place via an intermediate formed by the nucleophilic attack of a lithium reagent on the phosphorus atom.
Synthesis of Te‐alkyl carbamotelluroates from tellurium, carbon monoxide, amines, and alkyl halides
Authors: Inoue Toru , Mogami Toshiaki , Kambe Nobuaki , Ogawa Akiya , Sonoda Noboru 
Published: January 2005

AbstractLithium amides reacted with tellurium under atmospheric pressure of carbon monoxide to yield lithium carbamotelluroates which were trapped with alkyl halides to give Te‐alkyl carbamotelluroates in good yields. Results of control experiments suggested that lithium carbamotelluroates were formed by the reaction of tellurium with carbamoyllithiums generated in situ from lithium amides and carbon monoxide. It was revealed also that yields were improved when tellurium was preliminarily treated with lithium amides prior to the introduction of carbon monoxide into the reaction media.
The reaction of visnaginone, khillinone, and o‐hydroxy‐acetophenone with Lawesson's reagent
Authors: Shabana R. , Yakout E. M. , Atrees S. S. 
Published: January 2005

AbstractLawesson's reagent reacts with visnaginone (2a), khillinone (2b), and o‐hydroxyacetophenone (5) to give the 1,2‐oxaphosphinane derivatives 4a, 4b, and 6, respectively.
(Diazoalkyl)Phosphoranes from [4 + 1]‐cycloadditions of tetrahalo‐orthobenzoquinones to (diazoalkyl)phosphanes [1]
Authors: Nees Hans‐Joachim , Bergsträßer Uwe , Heydt Heinrich , Regitz Manfred 
Published: January 2005

AbstractThe (diazoalkyl)phosphanes 4a–e undergo [4 + 1]‐cycloaddition reactions with the tetrahalo‐orthobenzoquinones 5a,b to furnish the previously unknown (diazoalkyl)phosphoranes 6a–h. The structure of product 6h has been investigated by X‐ray crystallography.
Reactions of 2‐phospholene 1‐oxides with bromine in some media: Facile preparation of bromohydrin derivatives of 2‐phospholenes
Authors: Yamashita Mitsuji , Iida Akihito , Mizuno Hiroyuki , Miyamoto Yasushi , Morishita Toru , Sata Naoaki , Kiguchi Kenji , Yabui Akihiro , Oshikawa Tatsuo 
Published: January 2005

AbstractReactions of 1‐phenyl‐ and 1‐methoxy‐2‐phospholene 1‐oxides with bromine in aqueous organic solvents or in a protic medium, such as methanol, easily afforded the corresponding 2‐bromo‐3‐hydroxy‐ or 2‐bromo‐3‐methoxyphospholane 1‐oxide derivatives. The reaction mechanism was postulated based on the stereochemistry of the products.
1,5‐Dimethyl‐2,3,3,4‐Tetrachloro‐1,5‐Diaza‐2,4‐Diphosphorinan‐6‐One and some derivatives
Authors: Shevchenko I. V. , Krill J. , Schiebel H. M. , Schmutzler R. 
Published: January 2005

AbstractA synthesis of C‐chlorinated analogues of 1,5‐diaza‐2,4‐diphosphorinan‐6‐ones is described. The P‐chlorophosphine 3, a key compound for all reported substitution reactions, reacts in an unusual way with N,N′‐dimethyl‐N,N′‐bis(trimethylsilyl)urea to give the unsymmetrical product 5, the formation of which is accounted for by a silatropy of the intermediate compound 4. Compound 5 is stable in solution but rearranges quantitatively into isomer 6 without solvent at room temperature. Compound 3, its fluoro derivative 9, and the alkoxy derivatives 10a–d exist as cis‐and trans‐isomers. Some stereochemical aspects, as well as the possibility of 1,2‐chlorotropy, are discussed.
Fluorescent tricyclic β‐azavinamidine–BF2 complexes
Authors: Sathyamoorthi Govindarao , Soong Mou‐Ling , Ross Timothy W. , Boyer Joseph H. 
Published: January 2005

AbstractBoron trifluoride reacted with dipyrid‐2‐ylamine 6, its N‐methyl and 6,6′‐dimethyl derivatives 8 and 10, and 3,3′,5,5′‐tetraphenyl‐6‐azapyrromethene 13 to give fluorescent β‐azavinamidine (1,3,5‐triazapenta‐1,3‐diene) dyes: 10‐azapyridomethene–BF2 complex 5 (λf 422 nm, λlas 426 nm), its quaternary 10‐methyl tetrafluoroborate and 4,6‐dimethyl derivatives 9 (λf 362 nm) and 11 (λf 416 nm), and 1,3,5,7‐tetraphenyl‐8‐azapyrromethene–BF2 complex 17 (λf 696 nm). Treating 3,3′,4,4′‐tetraphenyl‐5,5′,6‐trimethylpyrromethene (prepared in situ from ethyl 3,4‐diphenyl‐5‐methylpyrrole‐2‐carboxylate in a reaction with acetyl chloride) with boron trifluoride gave 1,2,6,7‐tetraphenyl‐3,5,8‐trimethylpyrromethene–BF2 complex 21. Absorption for the vinamidine chromophore differed from that for the β‐azavinamidine chromophore by a hypsochromic shift of 86 nm in a comparison of pyridomethene–BF2 complex 3 with its 10‐aza derivative 5 and by a bathochromic shift of 105 nm in a comparison of the pyrromethene–BF2 complex 20 with the 8‐azapyrromethene–BF2 complex 17.
Structure and reactions of benzo‐4‐diphenylphosphino‐2‐phenyl‐1,3,2‐dioxaborinane
Authors: Nikonov G. N. , Balueva A. S. , Karasik A. A. , Litvinov I. A. , Prokhorova S. R. , Kataeva O. N. 
Published: January 2005

AbstractThe crystal structure of 5,6‐benzo‐4‐diphenylphosphino‐2‐phenyl‐1,3,2‐dioxaborinane 1 indicates the occurrence of an interaction between the π‐systems of the 1,3,2‐dioxaborinane ring and the appropriate phenyl group of the diphenylphosphino group. Complexes of compound 1 with PtCl2, PdCl2, and Cul were synthesized. Compound 1 and its complexes are readily hydrolyzed in solution to give diphenylphosphine and its corresponding complexes (NMR).