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  • 2H-Phosphirenes  (1)
  • Phosphaalkynes  (1)
  • Phosphinidene  (1)
  • Phosphorus dipolarophiles  (1)
  • 1
    Electronic Resource
    Electronic Resource
    A Theoretical Investigation of Cycloadditions of Hydrogen Isocyanide to CH2=X and PH=X Dipolarophiles (X = CH2, NH, O, SiH2, PH, S)We dedicate this paper to the memory of our friend and colleague, Prof. Dr. Gerrit L'Abbé, who untimely passed away on August 27, 1996. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 69-76 
    Details
    ISSN: 0009-2940
    Keywords: [2 + 1] Cycloadditions ; Hydrogen cyanide ; Phosphorus dipolarophiles ; Three-membered rings ; Calculations, ab initio ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We performed a systematic investigation of [2 + 1] cycloadditions of HN≡C to dipolarophiles of the type CH2=X and PH=X with X=CH2, NH, O, SiH2, PH, and S, as well as HN=NH and H2Si=SiH2. Ab initio MO calculations at the QCISD(T)/6-311G(d,p)/MP2/6-31G(d,p)+ZPE level were applied to construct the minimum-energy reaction pathways. Calculated results concerning the regiochemistry of the approaches and the stereochemistry of the product formation were analyzed in relation with established concepts such as frontier orbital, net charge distribution and stereoelectronic effect. For some systems, up to four distinct transition structures for cycloaddition were found. In general, there is a certain similarity between the behavior of both C and P series of dipolarophiles. The characteristics of the transition structures can be, in most cases, recovered by using qualitative concepts. The [2 + 1] cycloadditions are highly regioselective and stereospecific. Silicon-containing dipolarophiles are particularly attractive as they exhibit very small energy barriers to addition to isocyanides.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300111
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Remarkable Effect of Fluorine and Chlorine Atoms on the Stability of 1H-Phosphirene (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 923-927 
    Details
    ISSN: 0009-2940
    Keywords: 1H-Phosphirenes ; 2H-Phosphirenes ; Calculations, ab initio ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio MO calculations at the MP4/6-31G** level show that both fluorine and chlorine atoms exert a strong stabilizing effect on the three-membered ring 1H-phosphirene relative to its isomers. While unsubstituted 1H-phosphirene (12H) is the least stable C2H3P isomer, 1-fluoro-1H-phosphirene (12F) is calculated to be the global minimum of the C2H2FP potential energy surface; 1-chloro-1H-phosphirene (12Cl) is the third most stable of the six C2H2ClP isomers calculated. The remarkable stability of 12F is attributable to the particular strength of the P - F bond.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19921250425
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    A Density Functional Study of the Dimerization of Phosphaalkynes in the Presence of Transition Metal Fragments (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1281-1289 
    Details
    ISSN: 1434-1948
    Keywords: Phosphaalkynes ; Dimerization mechanism ; Diphosphacyclobutenes ; Density functional theory ; Ab initio calculations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dimerization of phosphaalkynes (R-C≡P, R = H, Me, tBu) without and with the presence of transition metal fragments, including CpCo (Cp = cyclopentadienyl) and COT-Ti (COT = cyclooctatetraene), has been probed using density functional theory calculations (B3LYP with different basis sets). MP2 and CCSD(T) calculations were also performed for the [H2C2P2] systems. In an attempt to address the exciting controversy and uncertainty about phosphaalkyne dimerization, a number of dimer formation mechanisms proposed in the literature have been examined. Some new and plausible intermediates have also been identified.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
  • 4
    Electronic Resource
    Electronic Resource
    Phosphinidene Transition Metal Complexes: A Combined Ab Initio MO-DFT Study of Cr(CO)5-PR (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 107-115 
    Details
    ISSN: 1434-1948
    Keywords: Ab initio calculations ; Density functional calculations ; Phosphinidene ; Carbonyl complexes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio MO and DFT calculations have been performed on phosphinidene complexes of the type Cr(CO)5-PR, with R = H, CH3, SiH3, NH2, PH2, OH, and SH. The formation of the Cr-P bond essentially arises from a ligand-to-metal charge transfer. While a significant π backdonation is also observed for the Cr(CO)5-PH, Cr(CO)5-PCH3, and Cr(CO)5-PSiH3 complexes, this is less the case for Cr(CO)5-POH, Cr(CO)5-PSH, and Cr(CO)5-PNH2, and the backbonding almost disappears for Cr(CO)5-PPH2. In both the lowest lying singlet and triplet states, all complexes exhibit a staggered conformation. CASSCF/CASPT2 calculations performed with the ANO basis sets indicate a closed-shell singlet ground state along the whole series. The binding energy between Cr(CO)5 and PR ranges from 216 kJ/mol for Cr(CO)5-PNH2 to 127 kJ/mol for Cr(CO)5-PSiH3 (B3LYP values). In general, the B3LYP-DFT scheme yields reasonable qualitative and quantitative results when compared with CASPT2(12/12).
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
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