Clam Structures of Metal-Biphenyl Complexes: M-C12H10 (M = Sc, La, Ti) BRAD SOHNLEIN, YUXIU LEI, and DONG-SHENG YANG Department of Chemistry University of Kentucky Lexington, KY 40506, USA $$ NSF & KSEF $$
Structure of Biphenyl Biphenyl is planar in the crystalline state In the gas phase, the phenyl rings are twisted
Structure of Biphenyl Biphenyl is planar in the crystalline state In the gas phase, the phenyl rings are twisted A balance between p-conjugation and steric repulsions
Metal-Biphenyl Complexes Good models for conducting organometallic polymers Two types of structures have been identified in the condensed phase No gas phase structural determination of M-biphenyl complexes
Experimental Apparatus biphenyl Sc, La, or Ti rod Nd:YAG UV
Sc-Biphenyl ZEKE Spectrum 0-0 39114 cm-1 FWHM ~ 8 cm-1 Ta Expt.
Sc-Biphenyl ZEKE Spectrum 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta 12 Expt.
Theoretical Methodology B3LYP and B3P86 implemented in Gaussian 03* Geometry optimizations and frequency analyses Calculate Franck-Condon integrals within the harmonic approximation Simulate spectra at finite temperatures using a Boltzman distribution * 6-311+G(d,p) for all atoms, except La atom (LanL2DZ ECP)
Sc-Biphenyl Electronic States ion 3A 1A Half-sandwich neutral 2A 4A
Sc-Biphenyl Electronic States Clam ion 3A 1A Half-sandwich 2A neutral 4A 2B1
Sc-Biphenyl Electronic States Clam ion 3A 1A Half-sandwich 4B1 neutral 2A 4A 2B1
Sc-Biphenyl Electronic States Clam 3A ion 1A Half-sandwich 1A1 4B1 neutral 2A 4A 2B1
Sc-Biphenyl Electronic States Clam 3B1 3A ion 1A Half-sandwich 1A1 4B1 neutral 2A 4A DS = 1 2B1
Sc-Biphenyl Electronic States Clam 3B1 3A ion 1A Half-sandwich 1A1 neutral DS = 1 xxxxxxxxxxxxxxxxxxxxx 2B1
Sc-Biphenyl Electronic States Clam 3B1 ion 1A1 ~ 44000 cm-1 neutral DS = 1 xxxxxxxxxxxxxxxxxxxxx 2B1
Sc-Biphenyl Electronic States Clam 3B1 3A ion 1A Half-sandwich 1A1 4B1 neutral 2A 4A DS = 1 xxxxxxxxxxxxxxxxxxxxx 2B1
Sc-Biphenyl ZEKE Spectrum 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. Half-sandwich
Sc-Biphenyl ZEKE Spectra 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. Half-sandwich * 3A 4A
Sc-Biphenyl ZEKE Spectra 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. Half-sandwich 3A 2A * 3A 4A
Sc-Biphenyl ZEKE Spectra 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. 1A 2A Half-sandwich 3A 2A * 3A 4A
Sc-Biphenyl ZEKE Spectra 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. Clam (C2v)
Sc-Biphenyl ZEKE Spectra 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. Clam (C2v) 3B1 4B1
Sc-Biphenyl ZEKE Spectra 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. Clam (C2v) 3B1 2B1 3B1 4B1
Sc-Biphenyl ZEKE Spectra 568 39114 cm-1 FWHM ~ 8 cm-1 378 336 284 Ta Expt. 1A1 2B1 Clam (C2v) 3B1 2B1 3B1 4B1
Observed Transition and Vibrations (cm-1) Expt. Theo.
Sc-Biphenyl Vibration Movies n17+ = 336 cm-1 n16+ = 378 cm-1 n15+ = 568 cm-1 n32+/ n32 = 142 / 155 cm-1
Further Experiments Is forming a clam structure dependent on: a.) size of metal—down the group b.) electronic species—across the row La-bp (size effect) and Ti-bp (electronic effect)
La-Biphenyl ZEKE Spectrum 0-0 36516 cm-1 FWHM ~ 6 cm-1 Expt.
La-Biphenyl ZEKE Spectrum 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt.
La-Biphenyl Vibration Movies n17+ = 257 cm-1 n16+ = 370 cm-1 n15+ = 532 cm-1 Not observed
Sc-Biphenyl Electronic States Clam 3B1 3A ion 1A Half-sandwich 1A1 4B1 neutral 2A 4A DS = 1 2B1
La-Biphenyl Electronic States Clam 3B1 3A 1A ion Half-sandwich 1A1 4B1 neutral 2A DS = 1 4A 2B1
La-Biphenyl Electronic States Clam 3B1 3A 1A ion 1A1 ~ 40700 cm-1 neutral DS = 1 xxxxxxxxxxxxxxxxxxxxx 2B1
La-Biphenyl Electronic States Clam 3B1 3A 1A ion Half-sandwich 1A1 4B1 neutral 2A DS = 1 4A xxxxxxxxxxxxxxxxxxxxx 2B1
La-Biphenyl ZEKE Spectrum 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt. Half-sandwich
La-Biphenyl ZEKE Spectra 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt. Half-sandwich 3A 4A
La-Biphenyl ZEKE Spectra 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt. Half-sandwich 3A 2A 3A 4A
La-Biphenyl ZEKE Spectra 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt. 1A 2A Half-sandwich 3A 2A 3A 4A
La-Biphenyl ZEKE Spectrum 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt. Clam (C2v)
La-Biphenyl ZEKE Spectra 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt. Clam (C2v) 3B1 4B1
La-Biphenyl ZEKE Spectra 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 Expt. Clam (C2v) 3B1 2B1 3B1 4B1
La-Biphenyl ZEKE Spectra 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 La Expt. 1A1 2B1 Clam (C2v) 3B1 2B1 3B1 4B1
La-Biphenyl ZEKE Spectrum 36 % narrower 5.5 3.5
La-Biphenyl ZEKE Spectra 257 36516 cm-1 370 FWHM ~ 6 cm-1 532 * La Expt. 1A1 2B1 Clam (C2v) 3B1 2B1 3B1 4B1
Further Experiments Is forming a clam structure dependent on: a.) size of metal—down the group b.) electronic species—across the row La-bp (size effect) and Ti-bp (electronic effect) Sc and La: (n-1)d1 ns2 Ti: (n-1)d2 ns2
Ti-Biphenyl ZEKE Spectrum Expt.
Ti-Biphenyl ZEKE Spectrum 194 Expt.
Ti-Biphenyl ZEKE Spectrum 350 194 Expt.
Ti-Biphenyl ZEKE Spectrum 350 194 194 Expt.
Ti-Biphenyl ZEKE Spectrum 350 194 326 194 Expt.
Ti-Biphenyl ZEKE Spectrum 350 194 326 Expt. 208 194 Expt.
Ti-Biphenyl ZEKE Spectrum 350 194 326 208 194 43842 0-0 350 Expt.
Ti-Biphenyl Electronic States Clam 2A ion Half-sandwich 4A 1A neutral 5A 3A
Ti-Biphenyl Electronic States Clam 2A ion Half-sandwich 4A 1A neutral 5A 3B1 3A 1A1
Ti-Biphenyl Electronic States Clam 2A 4B1 clam ? ion 2B1 Half-sandwich 4A 5A DS = 1 1A neutral 5A 3B1 3A 1A1
Ti-Biphenyl Electronic States Clam 2B1 ion 46700 cm-1 DS = 1 xxxxxxxxxxxxxxxxxxxxx neutral 1A1
Ti-Biphenyl ZEKE Spectrum 350 194 326 208 194 43842 350 Expt.
Ti-Biphenyl ZEKE Spectra 350 194 326 208 194 43842 350 Expt. 2B1 1A1
Ti-Biphenyl Vibration Movies n18 +/n18 = 194 / 208 cm-1 n17+/n17 = 350 / 326 cm-1
Summary 11 % overestimation
IE Overestimation by B3P86 Average ~ 10 % bz = benzene, np = naphthalene, phnp = phenyl-naphthalene, bp = biphenyl
Summary 10 % correction
Summary 10 % correction
Conclusions A new “clam” binding mode for biphenyl was identified Small (Sc) and large (La) metal atom coordination Different electron configurations: (n-1)d1 ns2 and (n-1)d2 ns2 Recorded first vibronic spectrum of a gas phase metal-biphenyl complex AIE measurements Metal- and ligand-based frequencies B3P86 overestimates IEs by ~ 10%
Thanks for your time
Size-dependent? Bond lengths: Increased radius by ~ 16 % Sc-Sc = 3.212 Å / 2 = 1.606 Å La-La = 3.739 Å / 2 = 1.870 Å Increased radius by ~ 16 % clam still formed What about Ti? Ti-Ti = 2.8956 / 2 Å = 1.448 Å valence electon configuration 4s23d2 CRC Handbook of Chemistry, 66th edition © 1985
La-biphenyl ZEKE spectrum 257 36516 cm-1 ~ 3.5 370 FWHM ~ 6 cm-1 532 La Expt. ~ 5.5 ~ 5.3 ~ 5.2
La-biphenyl ZEKE spectrum 36516 cm-1 ~ 3.5 FWHM ~ 6 cm-1 Expt. ~ 5.5 ~ 5.3 ~ 5.2
La-biphenyl ZEKE spectrum 5.5 3.5
Observed transition and vibrations (cm-1) IE overestimated by 13 % Expt. Theo.
Ti-biphenyl ZEKE spectrum FWHM ~ 15 cm-1 Expt.
Ti-biphenyl ZEKE spectrum 194 FWHM ~ 15 cm-1 Expt.
Ti-biphenyl ZEKE spectrum 350 194 FWHM ~ 15 cm-1 Expt.
Ti-biphenyl ZEKE spectrum 350 194 FWHM ~ 15 cm-1 194 Expt.
Ti-biphenyl ZEKE spectrum 350 194 FWHM ~ 15 cm-1 326 194 Expt.
Ti-biphenyl ZEKE spectrum 350 194 FWHM ~ 15 cm-1 326 194 208 Expt.
Ti-biphenyl ZEKE spectrum 350 194 FWHM ~ 15 cm-1 326 194 208 0-0 350 Expt. 43842 cm-1
Ti-biphenyl ZEKE spectrum 350 43842 cm-1 194 326 194 208 350 Expt. 4A 5A
Ti-biphenyl ZEKE spectrum 350 43842 cm-1 194 326 194 208 350 Expt. 4A 3A 4A 5A
Ti-biphenyl ZEKE spectrum 350 43842 cm-1 194 326 194 208 350 Expt. 2A 3A 4A 3A 4A 5A
Ti-biphenyl ZEKE spectrum 350 43842 cm-1 194 326 194 208 350 Expt. Clam 2B1 3B1 2A 3A 4A 3A 4A 5A
Ti-biphenyl ZEKE spectrum 350 43842 cm-1 194 326 194 208 350 Expt. Clam 2B1 1A1 2B1 3B1 2A 3A 4A 3A 4A 5A
Ti-biphenyl ZEKE spectrum 350 43842 cm-1 194 326 194 208 350 Expt. Clam 2B1 1A1 2B1 3B1 2A 3A 4A 3A 4A 5A
Observed transition and vibrations (cm-1) IE overestimated by 6 % Expt. Theo.
Observed transition and vibrations (cm-1) IE overestimated by 6 % Expt. Theo.