Microwave Spectrum, Structure, and Dipole Moment of Cyclopropylphosphine

Abstract

The microwave spectra of three isotopic species of cyclopropylphosphine have been analyzed. The conformation of the molecule is the symmetric one allowing maximum interaction of the lone pair electrons of phosphorus with the intra-annular orbitals of the cyclopropyl ring. A structure compatible with the observed moments of inertia yields, along with other parameters, a C-P bond distance of 1.834 A, distinctly shorter than that observed in other organic phosphine derivatives. The dipole moment is found to be 1.16 D.

The Ever‐Surprising Chemistry of Boron: Enhanced Acidity of Phosphine⋅Boranes

“…The preparation of methylphosphine (1), [19] phenylphosphine (3), [20] benzylphosphine (4), [20] chloromethylphosphine (5), [21] methylphosphine·borane (6), [22] phenylphosphine·borane (8), [22] and diborane [23] has already been reported, but several synthesis were partially modified in this work. Cyclopropylphosphine (2) [24] was prepared by reduction of the corresponding diethyl cyclopropylphosphonate 11. Experimental procedures for 1-6, 8, and 11 are given in the Supporting Information.…”

High Resolution Millimeter-Wave Spectroscopy of Cyclopropylphosphine–Borane

“…For the C–P bond, the results are quite similar to those of the title compound, that is, the MP2 value is smaller than the B3LYP value by 1.4 pm (184.0 pm at B3LYP and 182.6 at MP2). One should also note that, compared to the B3LYP values, the calculated MP2 rotational constants of cyclopropylphosphine agree better with the experimental ones . The calculated geometrical parameters and rotational constants of cyclopropylphosphine are given in Table S3 of Supporting Information.…”

“…Previous attempts to record the spectrum without a flow system were unsuccessful and only led to the observation of the free cyclopropylphosphine showing once again the easy breaking of the P–B bond in the gas phase at a low partial pressure . In the present study the recorded spectra were checked for the cyclopropylphosphine rotational lines, but no features that could be attributed to this compound were found. In general, no significant impurities have been observed because all the strongest lines in the spectra were assigned to CPPB.…”

Synthesis, Microwave Spectrum, Quantum Chemical Calculations, and Conformational Composition of a Novel Primary Phosphine, Cyclopropylethynylphosphine, (C3H5C≡CPH2)

“…The conformational, structural, and dynamical properties of many primary phosphines have been studied by microwave (MW) spectroscopy in the past. These studies include CH 3 PH 2 , (CH 3 ) 2 PH, , (CH 3 ) 3 CPH 2 , (CH 3 ) 3 P, (CH 3 ) 2 CHPH 2 , CH 3 CH 2 PH 2 , , cyclopropylphosphine (C 3 H 5 PH 2 ), phenylphosphine (C 6 H 5 PH 2 ), H 2 PCH 2 CH 2 CN, HCCPH 2 , H 2 CCHPH 2 , , H 2 PCH 2 CH 2 PH 2 , HCCCH 2 PH 2 , H 2 CCHCH 2 PH 2 , H 2 CCCHPH 2 , phosphirane (C 2 H 5 P), cyclopropylmethylphosphine (C 3 H 5 CH 2 PH 2 ), cyclopentadienylphosphine (C 5 H 5 PH 2 ), (chloromethyl)phosphine (ClCH 2 PH 2 ), and (2-chloroethyl)phosphine, (ClCH 2 CH 2 PH 2 ) . While one conformer exists for most of these phosphines, the existence of two or more rotameric forms have been seen for each of CH 3 CH 2 PH 2 , , H 2 PCH 2 CH 2 CN, H 2 PCH 2 CH 2 PH 2 , H 2 CCHCH 2 PH 2 , H 2 CCCHPH 2, C 3 H 5 CH 2 PH 2 , C 5 H 5 PH 2 , and ClCH 2 PH 2 .…”