bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of the Merrifield solid phase method on the design and synthesis of selective agonists and antagonists of oxytocin and vasopressin: A historical perspective
Authors: Manning Maurice 
Published: July 2007

AbstractThis tribute to Bruce Merrifield traces the author's fortuitous path in 1964 from Vincent du Vigneaud's laboratory to the laboratory of D. W. Woolley to learn the solid phase method and then to his first faculty position in the Department of Biochemistry, McGill University, Montreal in 1965. It recalls the key roles played from early 1966 to July 1967 by Bruce Merrifield, John Stewart, Arnold Marglin, Herb Takashima, and Vincent du Vigneaud in providing key advice to the author's efforts to use the solid phase method to synthesize oxytocin; while simultaneously the du Vigneaud and Merrifield laboratories were collaborating on the solid phase synthesis of deamino‐oxytocin. Both syntheses were published in the same issue of the Journal of American Chemical Society in 1968. Also described is how this breakthrough impacted the author's scientific career: by leading to highly productive collaborative studies, initially with Wilbur H. Sawyer and subsequently with others, on the design and synthesis of selective agonists, antagonists, and radioiodinated ligands for oxytocin and vasopressin receptors. These syntheses were greatly facilitated by the contributions of highly talented graduate students, research technicians, and visiting peptide chemists from Hungary, England, Poland, Bulgaria, and China. Many of these peptides have become very valuable pharmacological tools in studies on the peripheral and central effects of oxytocin and vasopressin: further attesting to the profound impact of the solid phase method as the cornerstone for all the discoveries, which he and his collaborators and coworkers have made over the past 40 years. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 203–212, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Synthesis and Bonding in Hybrid Diborolyl/Boranyl and Thiaboranyl Triple‐Decker Compounds – Electronic Contribution of Heteroborane Cluster Ligands in Complexes
Authors: Weinmann Wolfgang , Pritzkow Hans , Siebert Walter , Sneddon Larry G. 
Published: July 2007

AbstractThe three‐component reaction of [(η5‐C5H5)Co(η5‐(CEt)2(BEt)2CMe)]−, CoCl2and B9H−14(7) yields the triple‐decker complex [(η5‐C5H5)Co{μ,η5‐(CEt)2(BEt)2CMe}‐6‐Co(B9H13)] (8) with a terminal B9H13ligand contaning two cobalt–boron‐bridging hydrogen atoms. Analogously, (6‐H)−, CoCl2, andarachno‐6‐SB9H−12(10) react to give the triple‐decker [(η5‐C5H5)Co{μ,η5‐(CEt)2(BEt)2CMe}‐1‐Co‐2‐(SB9H9)] (11). The analogous reaction with the heteroboranyl anion arachno‐6,8‐S2B7H8−leads to the loss of one boron atom, forming the air‐stable triple‐decker complex [(η5‐ C5H5)Co{μ,η5‐(CEt)2(BEt)2CMe}‐7‐Co‐6,8‐(S2B6H8)] (12). The X‐ray structure determination shows that the dithiacobaltaborane fragment in12has an arachno cluster geometry. The three‐component reaction of (6‐H, CoCl2, and arachno‐2,3‐S2B9H10−yields the expected triple‐decker [(η5‐C5H5)Co{μ,η5‐(CEt)2(BEt)CMe}Co‐6,8‐(S2B9H9)] (15), and surprisingly the sandwich complex (η5‐C5H5)Co‐6,8‐(S2B9H9) (16). The constitutions of the new compounds are based on NMR and MS data. A rule is described regarding the electron donation of heteroboranyl cluster ligands in metal complexes.
Preparation, Properties, and Reactions, of Metal‐Containing Heterocycles, XCVI. Mono‐, Di‐ and Trinuclear Metallacycloalkanes of the Iron‐Triad
Authors: Lindner Ekkehard , Leibfritz Thomas , Fawzi Riad , Steimann Manfred 
Published: July 2007

AbstractThe reaction of the bis(triflates) [F3CSO3‐(CH)m‐O3SCF3] [m = 5–10, 12, 14, 16 (1a–i) with Na2[Os(CO)4] in dimethyl either affords the osmacycloalkanes 2a, 2b and 2f–i (m = 5, 6, 10, 12, 14, 16), diosmacycloalkanes 3a–i (m = 5‐10, 12, 14, 16), and triosmacycloalkanes 4a–i (m = 5–10, 12, 14, 16). The structure of 3f was investigated by an X‐ray structural analysis. This 22‐membered disomacycle crystallizes in the space group Pā with Z = 1. If the unsaturated cis‐4‐octen‐1,8‐diyl bis(trifluoromethanesulfonate) (5) is treated with Na2[Os(CO)4] the diosmacyclooctadeca‐5,14‐diene 6 is obtained. By treating the bis(triflates) 1a, b with Na2[Fe(CO)4] the corresponding ferracycloalkanes are formed only in situ. Insertion of carbon monoxide into the M–C σ bonds leads to the cyclic ketones 7a, d and to the diketone 8d.
New Five‐ and Six‐Coordinate Nitrosylosmium(0) and Nitrosylosmium(II) Complexes Prepared from the Stable 16‐Elektron Species [OsCl(NO)(PR)(PR3)2]
Authors: Werner Helmut , Flügel Ruth , Windmüller Bettina 
Published: July 2007

AbstractThe coordinatively unsaturated starting materials trans‐[OsCl(NO)PiPr3)2] (2) and trans‐ [(sCl(NO)(PiPr2Ph)2] (3), for which a new one‐pot synthesis is reported, react with isocyanides, SO2 and O2 to give the corresponding 1:1 adducts [OsCl(NO)(L)(P)(PiPr2R)2) (4–7). The corresponding methyleneosmium complex [OsCl(NO)(CH2)(PiPr3)2] (9), on treatment with SO2 and HCl, affords the six‐coordinate osmium(II) compounds [OsCl(NO)(K2(C,O)‐CH2S(O)O)()iPr3)2] (10) and [OsCl2(NO)(CH3(PiPr3)2]2] (11), respectively. The reactions of 2 and 3 with HCl, I2, CH3I, CH2CHBr, R'CO2H, PhSH, CH3OH, PhCOSH, and R'CHO lead by oxidative addition to the corresponding octahedral osmium(II) complexes [OsCl‐(NO)(X)(Y)(PiPr2R)2] (12–24). The initially formed compound [OsHCl(NO){SC(O)Ph}(PiPr3)2] (20a) rearranges smoothly to the more stable S‐bonded isomer [OsHCl(NO){OC(S)Ph}(PiPr3)2] (20b). Alkynyl(hydrid)‐ and diynyl(hydrido)‐osmium(II) complexes 20–31 and 34, 35 are obtained from 2 or 3 and HCCCO2/sb>Me, propargylic alcohols HCCCPh‐(R')OH or the diyne HCCCCCPh2OH. The compounds [OsHCl(NO)[CCCPh(R')OH)(PiPr3)2] (30, 31) react with aqueous HCl in benzene to give the η1‐allenylosmium(II) derivatives [OsCl2(NO)(η1‐CHCC(Ph)R'](PiPr3)2] (32, 33). [OsHCl(NO)(CCCCCPh2OH)(PiPR3)2] (34) has been characterized by X‐ray structural analysis.
Dinuclear Cobalt(II) Complexes of Pyrazole Ligands with Chelating Side Arms
Authors: Meyer Franc , Beyreuther Stefan , Heinze Katja , Zsolnai Laszlo 
Published: July 2007

AbstractA series of pyrazole‐based potential ligands bearing polydentate amine substituents in the 3‐ and 5‐positions of the heterocycle has been synthesized [3,5‐bis(R2NCH2)‐pyzH R2N = Me2N(CH2)3NMe (2aH), [Me2N(CH2)3]2N (2bH), (Et2NCH2CH2)2N (2cH)]. Upon reaction with two equivalents of CoCl2 they form complexes LCo2Cl3 (3a–c; L = 2a–c, respectively) which are shown crystallographically to contain a dinuclear metal core bridged by both the pyrazolate unit and a chlorine atom, with each cobalt center carrying a further terminal chlorine atom. Two of the ligand side arms in 3b, c are dangling, thus leading to five‐coordination of the cobalt(II) centers in all cases. Addition of two equivalents of NaBPh4 to solutions of 3b, c induced coordination of the formerly dangling side arms to the metal centers by substitution of the terminal chlorine atoms. The resulting compounds [LCo2Cl](BPh4)2 (4b, c, respectively) were characterized by X‐ray structure analyses. They can be viewed as dinuclear linked versions of tran‐type complexes [(tran = tris(aminoalkyl)amine] with distorted trigonal‐bipyramidal coordination spheres around cobalt(II). Conformational analyses employing force‐field calculations were carried out for 4b, c in order to rationalize the conformations observed in the solid state with regard to the accessible conformational space.
Polynuclear Gold(I) Complexes of Functionalized Thiols and Dithiols
Authors: López‐De‐Luzuriaga José M. , Sladek Alexander , Schneider Wolfgang , Schmidbaur Hubert 
Published: July 2007

AbstractTreatment of 2‐mercaptoaniline with {[(Ph3P)Au]3O}+ BF−4 leads to a regioselective auration to give the (2‐aminophenyl)sulfonium complex {(2‐H2NC6H4S[Au(PPh3)]2}+ BF−4 (1) as the sole product. With the same reagent, 4‐hydroxyphenyl)sulfonium salt 2, and 2‐mercaptopyridine is converted into the 2‐pyridylsulfonium salt 3. Dinuclear auration of the thiol functions is thus clearly favoured over the reaction at any of the other functional groups (–NH2, –py, –OH). As shown in earlier work, this is also true for HS‐functional carboxylic acids. With an excess of the oxonium reagent, however, 2‐mercaptosuccinic acid was now found to be converted into a tetranuclear complex with a doubly aurated sulfonium group and monoaurated carboxylate functions (4). Bis(2‐mercaptoethyl) ether and thioether react with the oxonium salt to give tetranuclear bis(sulfonium salts) 5, 6, with bifurcated {‐S[Au(PPh3)]2}+ groups at both ends. Structural studies of compounds 1, 5 and 6 showed the cations to be aggregated into centrosymmetrical dimers through short Au–Au contacts. Compound 5 forms one‐dimensional infinite chains through a similar aggregation via the two bifurcated sulfonium end groups of each individual dicationic unit. The dications of compound 6 are associated only into centrosymmetrical dimers leaving one of the two sulfonium groups of each unit without auriophilic contacts to neighbouring dications, probably owing to an internal Au–S contact with the thioether function.
Synthesis, Characterization and Polymerization Behavior of {(1R, S)‐2‐(η5‐9‐Fluorenyl)‐1‐[η5‐(1R,S)‐indenyl]‐1‐phenylethane}zirconium dichloride and {(1R,S)‐Cyclohexyl‐2‐(η5‐octahydro‐9‐fluorenyl)‐1[η5‐tetrahydro‐(1R,S)‐indenyl]ethane}zirconium Dichloride
Authors: Jany Gerhard , Repo Timo , Gustafsson Marina , Leskelä Markku , Polamo Mika , Klinga Martti , Dietrich Ulf , Rieger Bernhard 
Published: July 2007

AbstractEpoxystyrene (1a) were converted into their corresponding alcohols, 2a–c, by treatment with either fluorenyl‐ or indenyllithium. These alcohols were then further converted into their trifluoromethanesulfonate derivatives, 3a–c. Subsequent reaction of the triflates with fluorenyl‐, indolyl‐, or tetraphenylcyclopentadienyllithium resulted in formation of 2‐(9‐fluorenyl)‐1(1‐indenyl)‐1‐phenylethane (4a), and 1‐(9‐fluorenyl)‐2‐(5‐tetraphenylcyclopentadienyl)ethane (4c). The ansa‐metallocene (1‐(R,S)‐2(η5‐9‐fluorenyl)‐1‐[η5‐1(R,S)‐indenyl]‐1‐phenylethane]ZrCl2 (5a) was prepared from the dilithio salt of 4a. Hydrogenation of 5a with H2/PtO2 leads to {1(R,s)‐cyclohexyl‐2‐(η5‐octahydro‐9‐fluorenyl)‐1‐[η5‐tetrahydro‐1(R,S)‐indenyl]ethane]ZrCl2 (6a. The complexes 5a and 6a were activated with methylalumoxane (MAO) and used for propene polymerization. The solid state structures of 4b, 4c, and 5a are reported.
Synthesis of a Bisdienophilic Phthalocyanine and of Precursors for Repetitive Diels‐Alder Reactions Based on Hemiporphyrazines and Phthalocyanines
Authors: Stihler Patrick , Hauschel Bernd , Hanack Michael 
Published: July 2007

AbstractThe specific synthesis of a metal‐free bisdienophilic phthalocyanine 193, suitable for repetitive Diels‐Alder reactions, is reported. This was achieved by condensation of 191,3,3‐trichloro‐6/7‐nitroioindolenine (191) and 4,9‐dibutoxy‐2,3,5,8‐tetrahydro‐1,3‐diimino‐1H‐5,8‐epoxybenz[f]isoindoline (2). The ability of 3 to undergo Diels‐Alder reactions was tested by reaction with an excess of 1,2,3,4‐tetraphenylcyclopentadienone (5). Experimental data of the hemiporphyrazines 9, 10, and 11, which can be used as precursors for the synthesis of ladder polymers, are also given in the Experimental Section.
1,3‐Di‐tert‐butyl‐2,2,4,4‐tetrahalocyclodisilazanes ‐ Synthesis, X‐ray Crystal and Gas‐Phase Structures
Authors: Brönneke Christiane , Herbst‐Irmer Regine , Klingebiel Uwe , Neugebauer Peter , Schäfer Martina , Oberhammer Heinz 
Published: July 2007

AbstractThe syntheses of 1,3‐di‐tert‐butyl‐2,2,4,4‐tetrachlorocyclodisilazane (3) and of di‐tert‐butyl‐2,2,4,4‐tetrafluorocyclodisilazane (4) are reported. The X‐ray crystal structure of 3 and the electron‐diffraction gas‐phase structure of 4 have been determined. Both cyclodisilazanes possess planar four‐membered rings and nearly planar configurations at the nitrogen atoms. The Si‐N bond lengths are 171.1(1) pm and 170.6(3) pm and the Si ⃛Si transannular distances 245.0(1) and 241.3(13) pm in 3 and 4, respectively.
Chiral Polysiloxane‐Fixed Metal 1,3‐Diketonates (Chirasil‐Metals) as Catalytic Lewis Acids for a Hetero Diels‐Alder Reaction ‐Inversion of Enantioselectivity Upon Catalyst ‐Polymer Binding
Authors: Keller Fritz , Weinmann Hilmar , Schurig Volker 
Published: July 2007

AbstractA dimethylpolysiloxane chain is covalently bound to the monomeric Lewis acid catalyst (1R)‐(+)‐oxovanadium(1V) bis[3‐ heptafluorobutanoylcamphorate] [(+)‐5a] at the C‐10 position of the camphor moiety yielding the novel chiral polymeric (1S)‐( +)‐oxovanadium(1V) bis[3‐heptafluorobutanoylcamphorate] ‐dimethylpolysiloxane [( +)‐6a][1]. The Lewis acid promoted hetero Diels‐Alder reaction of trans‐l‐methoxy‐3‐(trimethylsilyloxy)‐ 1,3‐butadiene (1) and benzaldehyde (2) is studied in the presence of the enantiomerically pure monomeric (5a, 5b) and polymeric (6a, 6b) catalysts. The monomeric and polymeric catalysts of identical chirality[1] invoke opposite enantioselectivities toward the formation of 2‐phenyl‐ 2,3‐dihydro‐4H‐pyrone (4). This remarkable result is corroborated by numerous control experiments. Thus, it is demonstrated that the environment of the active site of the catalyst is changed when the complex is fixed to a polymeric chain. In contrast to 5 and 6, the monomeric 12 and polymeric 13 europium(III) tris[3‐heptafluorobutanoylcamphorates] of identical chirality invoke the same enantioselectivity toward the formation of 4. The concept of polymer attachment is utilized to recover the catalyst from the reaction mixture by precipitation and to recycle it for subsequent catalytic runs.
Preparation and Structures of Hexaphenyl‐ and Hexatolyltantalates(V)
Authors: Kleinhenz Sven , Schubert Mario , Seppelt Konard 
Published: July 2007

AbstractBy reacting TaCl5 with LiC6H5 and LiC6H4‐4‐CH3 salts, the anions Ta(C6H5)6 and Ta(C6H4‐4‐CH3)6 were obtained in small yields. They were structurally characterized by low‐temperature single‐crystal structure determination and found to have quite similar structures, which can be described as slightly distorted trigonal prismatic.
Reactive EC [p‐p] π Systems, 46 Syntheses and X‐ray Crystal‐Structure Analyses of Trifluoromethyl‐Substituted Ketiminodiselanes, Selenoamides and Selenoacrylamides
Authors: Blau Hanne , Grobe Joseph , Van Duc Le , Krebs Bernt , Läge Mechthild 
Published: July 2007

AbstractBis(trifluoromethylketiminoalkyl)diselanes [SeC(=NR)CF3]2 (6) [R = Me (a), iPr (b), tBu (c)] have been prepared in high yields (55‐70%) by reaction of the diselane (SeC2F5)2 (2) with RNH2. However, the analogous reaction of 2 with secondary amines, R2NH, results in the cleavage of the Se‐Se bond and leads to the N,N‐dialkyl‐2,2,2‐trifluoroselenoacetamides Se=C(NR2)CF3 (7) [R = Me (a), iPr (b)]. Cleavage of 6a‐6c with Me3SnH affords the selenoamides Se=C(NHR)CF3 (9) and the corresponding stannylselanes Me3SnSeC(=NR)CF3 (10) [R = Me(a), iPr (b), tBu (c)]. Selenoamides 7 and 9 can also be prepared from pentafluoroethylselenol HSeC2F5 (3), Se=C(F)CF3, (1) or its polymer [SeC(F)CF3]n (4) and primary or secondary amines. N,N‐dialkyl‐2‐methyl‐3‐fluoro‐4,4,4‐trifluoroselenoacrylamides Se=C(NR2)C(Me)=C(F)CF3[R = Et (13a), iPr (13b)] are prepared in moderate yields under mild conditions by treating either trifluoromethylselenocarbonyl fluoride (1) or its polymer [SeC(F)CF3]n with 1‐dialkylamino‐1‐propynes. The reaction proceeds by [2 + 2] cycloaddition and stereospecific electrocyclic ring‐opening, yielding, with respect to the resulting CC double bond, the E isomer as the only product. The molecular structures of 7b, 9a and 13b show the typical features of selenoamides with C(Se)‐N bond shortening and C‐Se bond elongation due to π interaction of the N lone pair with the CSe double bond. The observed perpendicular orientation of the selenoamide and the alkene units of 13b prevents π delocalization.
Synthesis and Structure of 2,2′ ‐Boryl‐, Germyl‐Silyl‐, and Stannyl‐Substituted 1,1′ ‐Binaphthyl Systems
Authors: Schilling Birgit , Kaufmann Dieter E. , Kaiser Volkier 
Published: July 2007

AbstractA number of Lewis acid binaphthyl systems, substituted in 2‐or 2,2′‐position, are synthesized by lithiation of 2,2′‐dibromo‐1,l ′‐binaphthyl (5), followed by addition of various electrophiles. Stepwise lithiation and subsequent borylation with trimethyl borate leads to the bromoboronic acid 6, which can be stabilized by esterification with pinacol giving 7. By increasing the reaction mixture to 2 equiv. of n‐butyllithium and 2 equiv. of methyl borate the path to the binaphthylmonoboronic acid ester 9 is opened up. A further increase in the quantity of electrophile also leads to the binaphthylbisboronic acid ester 12. The 2,2′‐disubstituted silyl, germyl, and stannyl derivatives 13a‐15a are accessible in good yields. Treatment with boron halides leads exclusively to methyl/halogen exchange, giving the bidentate Lewis acids 13b‐15b, the former of which can be bridged by oxygen.Only in case of the bis(tributylstannyl)binaphthyl 16a does ipso substitution occur in the presence of boron trichloride, giving the bis(dichloroboryl)‐substituted binaphthyl 16b which can then be hydrolysed to 11. The structures of the majority of the compounds were investigated by X‐ray diffraction. In case of the 2,2′‐disubstituted compounds 13a‐15a the naphthyl groups are orientated perpendicular to each other. The intra‐ and intermolecular interactions are dominated by this binaphthyl system. In case of the oxygenbridged compounds 13c and 14c the angle between the naphthyl planes decreases to about 70°. This also has an effect on the packing of the molecule; in this instance the orientation of two naphthyl in neighbouring molecules is nearly parallel. The structure of the diboronic acid is dominated by intra‐ and intermolecular hydrogen bonding.
Benzophenoneimine Complexes of Copper(1)
Authors: Schneider Wolfgang , Bauer Andreas , Schmidbaur Hubert 
Published: July 2007

AbstractThe reactions of [(MeCN)4Cu]BF4 with two or three equivalents of benzophenoneimine lead to the formation of [(Ph2CNH)2]BF4 (1) and [ (Ph2CNH)3Cu]BF4 (2), respectively. A further equivalent of the ligand does not coordinate to the cation of complex 2. The crystal structures of both compounds were determined. 1 shows a linearly two‐coordinated copper(I) center with a Cu‐N distance of 1.877(2) Å. In compound 2 a distorted trigonal planar coordination of copper is observed with N‐Cu‐N angles of 114.5(2), 112.9(2) and 132.4(2)°, corresponding to two nearly equal Cu–N distances [Cu–N2 1.947(5) and Cu–N3 1.934(5) Å] dnd a significantly longer third one (Cu‐N1 2.011(5) Å]. A comparison of these data with recently determined structures of bis(benzophenoneimine)silver(I) and ‐gold(I) complexes shows that the covalent radii of the monovalent coinage metals decrease in the order Ag(I) > Au(I) > Cu(I).
Temperature‐dependent Ring‐Opening and ‐Closure of a Cyclic Phosphane‐Borane
Authors: Sigl Marcus , Schier  , Schmidbaur Hubert 
Published: July 2007

AbstractA phosphane‐borane (3) with the P‐B bond integrated into a seven‐membered ring was prepared from 4‐pentenyl‐diphenylphosphane (4) by hydroboration using 9‐borabicyclononane (9‐BBN). The product was confirmed to have a ring structure in the solid state by single crystal X‐ray diffraction. The P‐B distance of 2.057(2) Å is indicative of a standard donor‐acceptor bond similar to the type found in homologous five‐ and six‐membered rings. The room‐temperature 31P‐NMR signal of the compound in various solvents (δ ≈ ‐ 15) is not compatible with the cyclic structure and suggests that ring opening occurs as the compound is dissolved. Variable‐temperature NMR work corroborated this assumption, and the enthalpy of ring closure was determined to be ΔH = ‐30.5(4) kJmol‐l. In CD2C12 at ‐90°C, δ31P is shifted to +3.5 ppm to low field, suggesting virtually complete ring closure under these conditions.
Flash Pyrolysis of 1,1,1‐Trimethyltetrasilane ‐ Evidence for the Formation of Dibridged Si2H2
Authors: Maier Günther , Reisenauer Hans Peter , Meudt Andreas , Egenolf Heiko 
Published: July 2007

AbstractPulsed flash pyrolysis of 1,1,l‐trimethyltetrasilane (5) led to trimethylsilane, silane and a further species which is believed to be dibridged Si2H2 (13). Another route to 13 was found in the cocondensation of hydrogen and silicon atoms in an argon matrix at 12 K. The identification of matrix‐isolated 13 is based on observed IR bands at 1475.6, 1092.8 and 890.3 cm−1. These positions are in good agreement with the ab initio calculated wavenumbers for the strongest absorptions of 13. The band shifts for the mono‐ and dideuterated isotopomers support this assignment.
Synthesis and Structures of Bis(tetramethylipiperidino)aluminum Halides‐X‐ray Crystal Structures of tmp2AlX (X = Cl, Br, I) and [tmp2A1(μ‐F)l2
Authors: Krossing Ingo , Nöth Heinrich , Tacke Christiane , Schmidt Martin , Schwenk Holger 
Published: July 2007

AbstractN‐Lithio‐2,2,6,6‐tetramethylpiperidine [Li(tmp)] reacts with AlX3 (X = Cl, Br) in diethyl ether/ n‐hexane solution to generate the products of substitution and ether cleavage, [tmpAl(X)(μ‐OEt)], (la, X = Cl; 1b, X = Br). However, when the reaction is allowed to proceed in n‐hexane alone, an almost quantitative yield of compounds tmp2AlX (2a, X = Cl; 2b, X = Br; 2c, X = I) is obtained. According to 27AI‐NMR spectroscopy, mass spectroscopy, cryoscopy, and X‐ray crystal structure determinations, these compounds are monomeric in the solid state, in solution, and in the gas phase. 2b reacts with AgBF4 yielding the fluoride‐bridged dimer (tmp2AlF), 2d, as shown by X‐ray crystal structure determination.
The Role of the 2,4,6‐Tris(trifluoromethyl)phenylamino Group in Stabilizing New Phosphorus‐, Arsenic‐, and Germanium‐Containing Main‐Group Compounds and Transition‐Metal Derivatives
Authors: Ahlemann Jens‐T. , Roesky Herbert W. , Murugavel Ramaswamy , Parisini Emilio , Noltemeyer Mathias , Schmidt Hans‐G. , Müller Olaf , Herbst‐Irmer Regine , Markovskii Leonid N. , Shermilovich Yuri G. 
Published: July 2007

AbstractThe reactions of potassium Rf‐amide [Rf = tris(trifluoromethyl)phenyl](2) with PCl3, AsC13, and GeC12 · dioxane yield new four‐membered inorganic heterocycles [RfNPCl]2 (3), [RfNAsC1]2 (4), and [RfNGe]2 (5), respectively. On the other hand, the reaction of Rf‐amide 2 with two equivalents of RfPCl2 leads to the formation of the imino‐γ3‐phosphane RfN=PRf (6) and the diamino‐γ3‐phosphane (RfNH)2PRf (7). The iminophosphane 6 reacts with Ni(CO)2(PPh3)2 and forms the complex [Ni(PPh3)2(RfN=PRf)] (9), in which the imino‐ phosphane coordinates to the metal through the phosphorus lone pair. Treatment of lithium amide 2 with transition metal chlorides ZnCl2 and FeCl2 yields the imido/amido spirocyclic metal derivatives 9 and 10, respectively. Compounds 3–10 have been extensively characterized by their analytical and mass, IR, and NMR (1H, 19F, and 31P) spectroscopy. Further, the molecular structures of all the compounds have been unambiguously determined by single‐crystal X‐ray diffraction studies. The diazadigermetidine 5 crystallizes in a fluorescent‐yellow orthorhombic and a yellow monoclinic crystal modification. The results obtained reveal the role of Rf, group in stabilizing new multiple bonded systems and inorganic heterocycles. A skeletal rearrangment of the Rf ligand is observed in the reactions leading to compounds 9 and 10. Moreover, the preparation of compounds 9 and 10 indicates the limitation of the use of this ligand in the preparation of new metal‐amide systems, especially where the metal atoms have a strong tendency for the formation of strong MF bonds.