Synthesis and properties of 1,2-(2,3-naphtho)-o-carborane

Abstract

length together with the moments of inertia from the microwave study8 to derive a value for the CPH angle. The value obtained is dependent on several assumptions but it lies between 97.3 and 99.6°for all reasonable assumptions. From the present study the CPF angle is found to be 97.8°. Thus, although the CPF angle in CH3PF2 may be smaller than the CPH angle in CH3PH2, the difference is definitely less than the 7.4°difference found in the amines, The dipole moment of CH3PF2 is 2.06 D; this is 0.74 D greater than the dipole moment of HPF2 ? A similar effect is found when we compare the dipole moments of CH3NF210(2.57 D) and HNF213 (1.92 D).After making several assumptions we have obtained a (13) D. R. Lide, J. Chem. Phys., 38, 456 (1963).value for the PC bond length of 1.82 A; this compares with a value of 1.858 A in CH3PH2.12 This shortening effect observed on introducing fluorine atoms is well known: the pH bond length in HPF2 is 1.412 A7 compared to 1.421A in PH3;14 the CN bond length in CH3NF2 is 1.449 A10 compared to 1.474 A in CH3NH2.9 Hence, with respect to structure, dipole moment, and barrier to internal rotation CH3PF2 behaves in just the manner expected from a consideration of related molecules.Acknowledgment. We acknowledge with appreciation the gift of a sample of CH3PF2 from Dr. K. Cohn.

Stable Agostic (C−H···M)closo-Irida- andcloso-Rhodacarboranes with σ,η2-Cyclooctenyl Ligands. Crystal and Molecular Structure ofcloso-3,3-(σ,η2-C8H13)-1,2-μ-(ortho-xylylene)-3,1,2-IrC2B9H9

“…Starting rhodium and iridium compounds [(η 4 -COD)RhCl] 2 , [(η 4 -COD)IrCl] 2 , and [Ir(η 4 -COD)(acac)] were prepared as described in the literature. The compound [ closo -1,2-μ-( ortho -xylylene)-1,2-C 2 B 10 H 10 ] was prepared and further degraded according to the literature methods. The 1 H, 11 B/ 11 B{ 1 H}, and 13 C/ 13 C{ 1 H} as well as the room- and low-temperature 2D correlation NMR spectra were recorded on Bruker AMX-400 ( 1 H at 400.13 MHz, 13 C at 100.61 MHz, and 11 B at 128.33 MHz) and Bruker DRX-500 ( 1 H at 500.13 MHz, 13 C at 125.76 MHz) spectrometers.…”

Synthesis, Structural Characterization, and Reactivity of ‘Carbons-Adjacent' nido- and arachno-Carborane Anions of the C2B10 Systems and Their Metal Complexes

“…Preparation of μ -1,2-[ o -C 6 H 4 (CH 2 ) 2 ]-1,2-C 2 B 10 H 10 (1). This compound was prepared using a modified literature method . To a solution of o -C 2 B 10 H 12 (7.20 g, 50.0 mmol) in a dry toluene/Et 2 O (2:1, 50 mL) was added a 1.60 M solution of n -BuLi in n -hexane (62.5 mL, 100.0 mmol) dropwise with stirring at 0 °C.…”

Photochemical synthesis of low-valent organothorium complexes. Evidence for photoinduced .beta.-hydride elimination

“…(3 ), 1.06 (3 ), and 2.54 (2 ) and a pair of symmetrical multiplets at 6.62 (2 H) and 6.82 (2 H). The singlet bridgehead proton absorption ( 2.54) was at almost the exact chemical shift which would be predicted for this molecule considering the chemical shifts of the benzylic protons of benzocyclobutene ( 3.14),10 the allylic protons of cyclobutene ( 2.54),'1 and the bridgehead protons of bicyclo[2.1.0]pent-2-ene ( 2.0).12 On the other hand, the bridgehead protons of the Dewar-o-xylylene species 8 are at 3.73.13 This, plus the fact that 8 is relatively stable thermally, makes the alternative photoproduct structure 9 highly unlikely. The ready thermal reconversion of the photoproduct to isoindene 1 taken together with the simplicity of the NMR spectrum makes dimeric structures highly improbable.…”