# Last edited on 2013-02-12 04:33:27 by stolfilocal J. S. Ward and R. Pettit J. Chem. Soc. D, 1970, 1419-1420 DOI: ! (done) odium tetracarbonylferrate reacted with (I) 3-chloro-2-(chloromethyl)propene in ! (done) etrahydrofuran to give trimethylenernethaneiron tri- ! (done) arbonyl ! (done) ! (done) odium pentacarbonylmolybdenate reacted with (I) to ! (done) ive trimethylenemethanemolybdenum tetracarbonyl (IIb) ! (done) s yellow crystals (mp. 50°, 1%) as well as the complex ! (done) IV) Mo (C8H12) (CO)3 as orange needles [m.p. 62 ° (decomp.), 2% / , ] . ! (done) ! (done) ! (done) rradiation of an ether solution of Cr(CO), in the presence ! (done) f (I) gave triinethylenemethanechromium tetracarbonyl ! (done) IIc) as yellow needles (n1.p. 8 3 O , ~ 1 % ! (done) ---------------------------------------------------------------------- from ---------------------------------------------------------------------------------- from In 1976, the triplet multiplicity of the ground state of TMM was confirmed by the EPR experiment. 33 Dowd had also attempted to determine the singlet–triplet splitting in TMM, 34,35 which was measured later by photoelectron spectroscopy. 38 Recently, the infrared spectrum of the triplet ground state was reported. 36,37 Additional information about TMM’s vibrational frequencies was derived from the photoelectron spectrum of the corresponding anion. 39 ! (done) Ground triplet state: ! (done) ! (done) {{chem|3|A|2}}'/{{chem|3|B|2}}, D3h geometry ! (done) ! (done) Three singlet states: ! (done) ! (done) The first three singlet states are ! (done) ! (done) The first closed-shell 1{{chem|1|A|1}} singlet (of a diradical type) (1.17 eV above ground state) is exactly degenerate in D3h ! (done) symmetry ! (done) ! (done) The open-shell 1{{chem|1|B|2}} singlet (of a diradical type) (1.17 eV above ground state) is exactly degenerate in D3h ! (done) symmetry ! (done) one CHC twisted at 79 degrees, C-H 1.076, C-C 1.482 C-C-H 120.8 degr ! (done) two CHC planar, C-H 1.075 and 1.077, C-C 1.375, C-C-H 121.6 and 120.8, ! (done) central C-C-C 119.2 ! (done) ! (done) The second closed-shell singlet 2{{chem|1|A|1}}/{{chem|1|A|1}}' (3.88 eV) is stabilized at the planar C2v geometry, ! (done) with one short CC bond. Its equilibrium geometry is of D3h symmetry. ! (done) ! (done) The open-shell singlet prefers an equilibrium ! (done) structure with one long CC bond and a twisted methylene group ! (done) (planar C2v structure with one long CC bond corresponds to ! (done) a transition state between two equivalent minima) ! (done) ! (done) ! (done) ! (done) The next two states, 1{{chem|3|A|1}} and 2{{chem|3|B|2}} (4.61 eV), are degenerate triplets ! (done) derived from excitations of one electron. ! (done) ! (done) The quintet {{chem|5|B|2}} state (7.17 eV) has all the p orbitals singly ! (done) occupied and prefers D3h geometry --------------------------------------------------------------------> i Trimethylenemethane Trimethylenemethane was prepared by the reaction of potassium vapor3 with 2-iodomethyl-3-iodopropene 200-mm helium atmosphere Dimerizes in gas phase to 1,4-dimethylenecyclohexane; forms and 2-methylpropene by the abstraction of two hydrogen atoms from neighboring hydrocarbon or potassium hydride t trimethylenemethane does not react with ethene ---------------------------------------------------------------------- Trimethylenemethane from Photolysis of 3-Methylenecyclobutanone First PageHi-Res PDF[265 KB]Citing Articles Paul. Dowd , Krishna. Sachdev Journal of the American Chemical Society, 1967, 89 (3), pp 715–716 {{doi|10.1021/ja00979a057 Publication Date: February 1967 Direct irradiation of a dilute (5 pl in 1 ml) solution of 3- methylenecyclobutanone (11) in perfluorodimethyl- cyclobutane or perfluoromethylcyclohexane3 at - 196 O f wavelength 270-310 nm ---------------------------------------------------------------------- .eta.3-Trimethylenemethane Complex of Platinum First PageHi-Res PDF[788 KB]Citing Articles Veronique Plantevin , Patrick W. Blosser , Judith C. Gallucci , Andrew Wojcicki Organometallics, 1994, 13 (9), pp 3651–3656 {{doi|10.1021/om00021a044 Publication Date: September 1994 [TMM derivatives not plain TMM] ---------------------------------------------------------------------- Synthesis and reactivities of tungsten complexes with disubstituted trimethylenemethane ligands First PageHi-Res PDF[958 KB] Iuan Yuan Wu , Ming Chu Cheng , Ying Chih Lin , Yu Wang Organometallics, 1993, 12 (5), pp 1686–1693 {{doi|10.1021/om00029a029 Publication Date: May 1993 [TMM derivatives not plain TMM] ---------------------------------------------------------------------- Triplet electronic ground state of trimethylenemethane First PageHi-Res PDF[659 KB]Citing Articles David R. Yarkony , Henry F. Schaefer III Journal of the American Chemical Society, 1974, 96 (12), pp 3754–3758 {{doi|10.1021/ja00819a007 Publication Date: June 1974 [Theoretical] ---------------------------------------------------------------------- Tetrahedron Volume 41, Issue 2, 1985, Pages 297–307 The bimolecular reactions of trimethylenemethane diradicals with acrylonitrile and molecular oxygen William R. Dolbier Jr., Conrad R. Burkholder Department of Chemistry, University of Florida Gainesville, Florida 32611 USA http://dx.doi.org/10.1016/S0040-4020(01)96421-X, How to Cite or Link Using DOI Permissions & Reprints [TMM derivatives trapped by O2 to form peroxoethers, reveal equilibrium.] ---------------------------------------------------------------------- Photoelectron Spectroscopy of the Trimethylenemethane Negative Ion. The Singlet-Triplet Splitting of Trimethylenemethane † Paul G. Wenthold, ‡ Jun Hu, § Robert R. Squires,* ,§ and W. C. Lineberger* ,‡ J Journal of the American Chemical Society 1996, 118, 475-476 Ab initio molecular orbital and valence-bond calculations predict values of 14-20 kcal/ mol for the energy splitting between the X÷ 3 A′2 state and the a˜ 1 B1 state, 1a, which has one methylene group twisted out of the plane of the molecule. 14,15 T Dowd and Chow17 report an experimental estimate of 7 kcal/mol for the singlet-triplet splitting in 1, We now report the photoelectron spectrum of the trimethylenemethane negative ion 1 ¥- . From this spectrum we have obtained the electron affinity and singlet-triplet splitting of planar TMM. The results are in good agreement with the theoretical predictions and further support the contention that the estimated splitting based on the EPR data of Dowd and Chow is too low t this ion can be prepared in high yield in the gas phase by the reaction of 2-[(trimethylsilyl)methyl]allyl anion with molecular fluorine, F2 (Scheme 1). 19 The value obtained for the X÷ 3 A′2-b÷ 1 A1 energy splitting, 0.699 ( 0.006 eV (16.1 ( 0.1 kcal/mol), is within the range predicted by the ab initio calculations. 14,15 This suggests that the 1 B1 state lies 13-16 kcal/ mol above the triplet state. ---------------------------------------------------------------------- (9) Jacobs, S. J.; Schultz, D. A.; Jain, R.; Novak, J.; Dougherty, D. A. Journal of the American Chemical Society 1993, 115, 1744 Practical application: organic ferromagnet ---------------------------------------------------------------------- Journal of Chemical Physics / Volume 72 / Issue 3 Previous Article | Next Article FULL-TEXT OPTIONS: Download PDF Permissions / Reprints J. Chem. Phys. 72, 1463 (1980); http://dx.doi.org/10.1063/1.439370 (8 pages) A single crystal EPR study of ground state triplet trimethylenemethane O. Claesson1, A. Lund1, T. Gillbro1, T. Ichikawa2, O. Edlund2, and H. Yoshida2 Trimethylenemethane, a ground state triplet, has been generated in a single crystal of methylenecyclopropane by γ irradiation at 77 K and studied by the electron paramagnetic resonance technique in the temperature range 4.2–106 K. ----------------------------------------------------------------------