%0 Journal Article %1 Bruns.1993b %A Bruns, Wolfgang %A Hausen, Hans-Dieter %A Kaim, Wolfgang %A Schulz, Andreas. %D 1993 %J Journal of Organometallic Chemistry %K carbonyl crystal methyl methylpyrazinium phosphine phosphine;ESR phosphine;electrochem radical;pyrazinium redn structure tungsten %N 1-2 %P 121--130 %T Tungsten(0) complexes of p-acids N-methylpyrazinium cations and of N-methylpyrazinium radicals. Crystal and molecular structure of [(C4H4N2-Me)W(CO)3(PCy3)2](PF6), Cy = cyclohexyl %V 444 %X Bonding characteristics of the H2-coordinating 16 valence electron species W(CO)3(PR3)2 (R = CHMe2, cyclohexyl (Cy)) were detd. by studying stable complexes with the poorly 2 electron-donating but strongly p-accepting cationic ligand N-methylpyrazinium (mpz+). In comparison with the related complex with W(CO)5, the 1H NMR and electrochem. data suggest a strong degree of p back-donation from W(CO)3(PR3)2 to the cationic acceptor in the ground state. This view is supported by the crystal structure anal. of [(mpz)W(CO)3(PCy3)2](PF6) which reveals a trans,mer configuration with a short W-N bond (210.1(10) pm). Crystal data: monoclinic, space group P21/c, a 9.079(2), b 12.859(3), c 40.981(1) \AA, b 91.19(1)°, Z = 4, R = 0.067, Rw = 0.059. Redn. to the N-methylpyrazinium radical complexes yields highly resolved ESR spectra which show the loss of 1 phosphine ligand in the case of the tricarbonyl complexes. Even the W(CO)3(PR3) fragment induces considerable spin delocalization from the pyrazinium radical ligand to the metal. [on SciFinder(R)]

@article{Bruns.1993b, abstract = {Bonding characteristics of the H2-coordinating 16 valence electron species W(CO)3(PR3)2 (R = CHMe2, cyclohexyl (Cy)) were detd. by studying stable complexes with the poorly 2 electron-donating but strongly \textgreek{p}-accepting cationic ligand N-methylpyrazinium (mpz+). In comparison with the related complex with W(CO)5, the 1H NMR and electrochem. data suggest a strong degree of \textgreek{p} back-donation from W(CO)3(PR3)2 to the cationic acceptor in the ground state. This view is supported by the crystal structure anal. of [(mpz)W(CO)3(PCy3)2](PF6) which reveals a trans,mer configuration with a short W-N bond (210.1(10) pm). Crystal data: monoclinic, space group P21/c, a 9.079(2), b 12.859(3), c 40.981(1) {\AA}, \textgreek{b} 91.19(1)°, Z = 4, R = 0.067, Rw = 0.059. Redn. to the N-methylpyrazinium radical complexes yields highly resolved ESR spectra which show the loss of 1 phosphine ligand in the case of the tricarbonyl complexes. Even the W(CO)3(PR3) fragment induces considerable spin delocalization from the pyrazinium radical ligand to the metal. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Bruns, Wolfgang and Hausen, Hans-Dieter and Kaim, Wolfgang and Schulz, Andreas.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/22ffe62e0c61210ba01f79b794a93bfae/huebleriac}, interhash = {031d8563fae95f6015ad14edd3d9cbe3}, intrahash = {2ffe62e0c61210ba01f79b794a93bfae}, journal = {Journal of Organometallic Chemistry}, keywords = {carbonyl crystal methyl methylpyrazinium phosphine phosphine;ESR phosphine;electrochem radical;pyrazinium redn structure tungsten}, number = {1-2}, pages = {121--130}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Tungsten(0) complexes of \textgreek{p}-acids N-methylpyrazinium cations and of N-methylpyrazinium radicals. Crystal and molecular structure of [(C4H4N2-Me)W(CO)3(PCy3)2](PF6), Cy = cyclohexyl}, volume = 444, year = 1993 }