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  • 1
    Electronic Resource
    Electronic Resource
    The electronic structure and aromaticity of 1,3-azaphosphole and 1,3-azarsole (1992)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 96 (1992), S. 623-626 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100181a021
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  • 2
    Electronic Resource
    Electronic Resource
    The photoelectron spectrum and conformation of phenylphosphine and phenylarsine (1995)
    Springer
    Structural chemistry 6 (1995), S. 1-7 
    Details
    ISSN: 1572-9001
    Keywords: UV photoelectron spectroscopy ; ab initio quantum-chemical calculations ; phenylphosphine ; phenylarsine ; o-phosphinophenol ; o-arsinoaniline ; conformation ; rotational barrier
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract He(I) and He(II) photoelectron spectra of phenylphosphine and phenylarsine have been investigated and assigned. The rotational barrier of the phosphino group has been investigated at the MP2/6-31G(d,p)//MP2/6-31G(d,p) and HF/6-31G(d,p)//HF/6-31G(d,p) levels of theory, and that of the arsino group at the HF/6-31G(d,p)//6-31G(d,p) levels of theory. The rotational barrier of the two molecules is nearly the same. The energy difference between the two possible conformers of the molecules is low (1.5 kJ/mol at the MP2/6-31G(d,p) level of theory), allowing nearly free rotation about the P-C bond. The photoelectron spectrum cannot be interpreted by considering the most stable rotamer, but all possible conformers should be taken into account. The present interpretation is consistent with the smalln p - π interaction concluded from other investigations. The rotational barrier ofo-phosphinophenol is significantly larger than for phenylphosphine, and the photoelectron spectrum of this compound can be interpreted by considering a single conformer, and no appreciable interaction between the π-system of the ring and the phosphorus lone pair.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02263522
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  • 3
    Electronic Resource
    Electronic Resource
    P/O Ligand Systems: Synthesis, Reactivity, and Structure of Tertiary o-Phosphanylphenol Derivatives (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 431-431 
    Details
    ISSN: 0009-2940
    Keywords: o-Phosphanylphenols ; P,O hybrid ligands ; P asymmetry ; C,O-dilithium reagents ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300320
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  • 4
    Electronic Resource
    Electronic Resource
    Neue σ2λ3-P=C - O-Systeme: Stabile nichtkonjugierte Phosphaalkenether - Synthese und Reaktionen (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 493-496 
    Details
    ISSN: 0009-2940
    Keywords: Phosphaalkene ethers ; 1,3-Oxaphospholes, dihydro- ; 1,3-Oxaphosphorines, tetrahydro- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New σ2λ3-P=C - O Systems: Stable Non-Conjugated Phosphaalkene Ethers - Synthesis and ReactivityNon-conjugated cyclic phosphaalkene ethers (2, 4, 6) are obtained by cyclocondensation of (2- or 3-hydroxyalkyl)phosphanes 1, 3 with N-arylpivalimidoyl chlorides. Hydrolysis of 2, 4 with H2O (→7, 8), addition of hydrogen compounds (HCl, HSPh, MePhPH) (→ 9-12), and oxidation with air (→ 14) are studied. The reactivity of the title compounds and of benzoxaphospholes are compared.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911240312
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  • 5
    Electronic Resource
    Electronic Resource
    P/O Ligand Systems: Facile Synthesis, Structure, and Catalytic Tests of 2′-Phosphanyl-1,1′ -phenyl-2-ols and 2′-Phosphanyl-1,1′-binaphthyl-2-ols (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1663-1670 
    Details
    ISSN: 0009-2940
    Keywords: Lithiation ; P ligands ; NMR spectroscopy ; Molecular structure ; Hydrogenations ; Hydroformylations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A facile synthesis of 2′-phosphanyl-1,1′-biphenyl- and 2′-phosphanyl-1,1′ -binaphthyl-2-ols and their silyl ethers has been developed, consisting of electron-transfer-catalyzed ring-opening of dibenzofuran and dinaphthofuran, respectively, subsequent reaction with chlorophosphanes, and work-up with acetic acid or ClSiMe3. Studies of the molecular and crystal structures reveals the presence of P - H - O bridging bonds in the more basic tBuPhP derivative and a nearly perpendicular arrangement of the aryl planes in the biphenyl derivatives. The barrier to rotation of the aryl planes about the C-C axis was determined by NMR in the case of the P-asymmetric derivative 3d, using the appearence of diastereoisomers by atropisomerism and P-asymmetry. Comparative screening tests of the title compounds, phosphanyl phenols and phosphanylnaphthols in homogeneous Rh-catalyzed reactions demonstrate catalytic activity in hydroformylation reactions and superior properties of the biphenyl- and binaphthyl-2-ol derivatives in relation to other P-O ligands.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971301118
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  • 6
    Electronic Resource
    Electronic Resource
    Syntheses, Structures, and Reactivity of 1-Phosphanylnaphth-2-ols (1996)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 1061-1071 
    Details
    ISSN: 0009-2940
    Keywords: Phosphanylnaphthol ; PO ligands ; Chelate complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: P-tertiary or amino-substituted 1-phosphanylnaphth-2-yl silyl ethers 3 are synthesized by stepwise reaction of lithium 1-lithio-2-naphtholate 1 with chlorophosphanes and ClSiMe3. The free phosphanylnaphthols 4 are prepared by alcoholysis. As established by characteristic coupling constants and X-ray structural analyses (of 3c, 4c), 3 exhibit in solution and in the solid state a cis-bisecting conformation, whereas 4 prefers the opposite trans-bisecting arrangement, allowing easy protonation and formation of chelate complexes. Substitution reactions of phosphanylnaphtholates 2 with Ph2PCl and formation of chelate complexes LNi-η5-Cp and L2Pd are described. Attempts to prepare secondary and primary phosphanylnaphthols failed because of facile cleavage of the P-C(naphthyl) bond in PH-substituted 1-phosphanylnaphth-2-ols.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19961290914
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  • 7
    Electronic Resource
    Electronic Resource
    P/O Ligand Systems: Synthesis, Reactivity, and Structure of Tertiary o-Phosphanylphenol Derivatives (1996)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 1547-1560 
    Details
    ISSN: 0009-2940
    Keywords: o-Phosphanylphenols ; P,O hybrid ligands ; P asymmetry ; C,O-dilithium reagents ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of C,O-dilithium reagents 1 (M = M′ = Li) or C,O-lithium-sodium reagents 1 (M = Li, M′ = Na) with chlorophosphanes afford C,O-disubstitution products 2 or phosphanylphenolates 3 which are treated subsequently with ClSiMe3 to give 4-methyl- and bulky 4,6-di-tert-butyl substituted o-phosphanylphenol silyl ethers 4. These were applied for the preparation of the corresponding o-phosphanylphenols 5, mainly P-asymmetric derivatives. Limitations and side reactions by use of 1 in the above synthesis are discussed. Acid-base properties, pH-dependent solubility in water/hexane, and substitution reactions at oxygen and phosphorus of selected representatives of 5 are reported. An example for the separation of enantiomers by esterification with (1S)-(—)-camphanic acid chloride is given. IR studies revealed intramolecular P-H—O bonds and 2J(PC) the preferred trans arrangement of the phenoxy group in solution. In the solid state, inter- and intramolecular P-H—O bonds were detected by X-ray structure analysis. The trans arrangement of the phenoxy group is preserved. Because of steric hindrance, the O substituents are tilted towards the phosphorus atom and thus induce large through-space coupling constants. The P-Sn distance of 336.9 pm in the bulky substituted O—SnMe3 moiety 8h is however too large for the formation of genuine intramolecular coordination. The versatility of o-hydroxyarylphosphanes and objectives of further studies are shown by preliminary results on complex formation and applications of these phosphanes in catalysis.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19961291223
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  • 8
    Electronic Resource
    Electronic Resource
    Nickel Chelate Complexes of 2-Alkylphenylphosphanylphenolates: Synthesis, Structural Investigation and Use in Ethylene Polymerization (2000)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 299-305 
    Details
    ISSN: 1434-1948
    Keywords: Phosphanylphenolate ; Cyclopentadienylnickel complexes ; Chelates ; Ethylene polymerization ; Crystal structure ; Polymerizations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Diphenylphosphanyl- and 2-alkylphenylphosphanyl-4-methylphenols 1 or their silyl ethers 2 and equimolar amounts of nickelocene react in benzene preferably to give orange-brown diamagnetic cyclopentadienylnickel chelate complexes [η-CpNi(P∩O)] (3). Addition of a second equivalent of 1 or 2 affords (RR) and (SS) diastereoisomers of cis-bis(P∩O-chelates) 4a-c (R = Ph, Me, iPr) or the unsymmetrical cis-bis(P∩O-chelate) 5, whereas with bulkier substituted derivatives 1d or 2d (R = tBu) the second step is hindered or retarded. The reactivity of 1d remains high towards nickel salts in polar solvents, but in contrast to 1a-c, yielding 4, a sparingly soluble green trans-bis(P-O-chelate) nickel complex 6d is formed. Complexes formed in situ from 1 or 2 and Ni(COD)2 in toluene catalyze the polymerization of ethylene. The cyclopentadienyl (P∩O) complexes 3, however, are too stable to be active in this process. The crystal and molecular structure of 3c and 4c are described.Supporting information for this article is available on the WWW under -//_/_http://www.wiley-vch.de/contents/jc_2005/2000/99035_s.pdf or from the author.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Complexes of Azaphospholes: Synthesis and Structure of Pentacarbonyl-(η1)-2-phosphaindolizine)chromium(0), -molybdenum(0), and -tungsten(0) (1998)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 1079-1086 
    Details
    ISSN: 1434-1948
    Keywords: Phosphorus heterocycles ; P ligands ; Transition metals ; Carbonyl complexes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The complex chemical behaviour of 2-phosphaindolizines 1 (1,3-azaphospholo[1,5-a]pyridines) towards metal carbonyl compounds was studied. (η1-2-Phosphaindolizine)M(CO)5 complexes 2-4 (M = Cr, Mo, W) were formed from 1 and [(THF)M(CO)5], the cis-L2Cr(CO)4 complex 5f from 1f and tetracarbonyl(norbornadiene) chromium(0). The reaction of 2-phosphaindolizines 1e, 1f, or 1g with tricarbonyl(cycloheptatriene)molybdenum(0) or tricarbonyl(mesitylene)tungsten(0) yielded σ-complexes of the types L2M(CO)4or L3M(CO)3 rather than isolable π-complexes. In one case a strong upfield signal (δ31P = 6.1) was observed with a coordination shift of Δδ = -161.7, which is typical for π-coordination. Prolonged reaction or work-up led, however, to dismutation yielding 1g and the fac-L3Mo(CO)3 complex 6g. X-ray structure analysis of 2a indicates an increased 10π-delocalization compared with 1a and a changed conformation of the acyl substituent. The influence of substituents and metals on the 31P and 13C complexation chemical shifts and coupling constants is discussed.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Methyl(2-phosphanylphenolato[P,O])nickel(II) Complexes - Synthesis, Structure, and Activity as Ethene Oligomerization Catalysts (2000)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 431-440 
    Details
    ISSN: 1434-1948
    Keywords: Methylnickel complexes ; 2-Phosphanylphenolate ; Chelates ; Homogeneous catalysis ; Oligomerization ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of various substituted 2-phosphanylphenols 1a-f with half-molar amounts of cis-[MeNi(μ-OMe)(PMe3)]2 have been found to yield square-planar methyl(2-phosphanylphenolato)(trimethylphosphane)nickel(II) complexes 2a-f. 2JPP coupling constants of 305-316 Hz at low temperature indicate a trans-configuration for the products, while broad 31P-NMR signals at room temperature can be attributed to rapid dissociation of PMe3. Reaction with excess 1 gave rigid bis(2-phosphanylphenolato)nickel(II) complexes as exemplified by 3e, whereas addition of PMe3 to 2a led to the pentacoordinate methyl(2-phosphanylphenolato)bis(trimethylphosphane)nickel(II) complex 4a. Higher yields of 4a and 4d were obtained by reactions of 1a and 1d with Me2Ni(PMe3)3. Single-crystal X-ray diffraction analyses of 3e and 4a have revealed the structures as square-planar trans-bis- and trigonal-bipyramidal mono(2-phosphanylphenolato)nickel(II) P1O-chelate complexes, respectively. The methylnickel complexes 2 and 4 have been found to be effective one-component catalysts for the oligomerization of ethene. High conversions (〉 96%) were achieved with the P-basic derivatives 2e, 2f, and 4d bearing one or two branched alkyl groups (isopropyl, tert-butyl), whereas the diphenylphosphanyl derivatives were less active; 4d gave shorter oligomers than 2e or 2f.
    Additional Material: 4 Ill.
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