1. Millimeter-Wave Studies of the Isotopologues of IZnCH 3 (X 1 A 1 ) : Geometric Parameters and Evidence for Zinc Insertion M. P. BUCCHINO and L. M. ZIURYS Department of Chemistry, Astronomy and Steward Observatory, University of Arizona J. P. YOUNG and P. M. SHERIDAN Department of Chemistry and Biochemistry, Canisius College

2. Why Study IZnCH 3 ? J. Org. Chem. 2008, 73, 3680 – 3688 Nobel Prize in Chemistry 2010 Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki Negishi Pd-catalyzed cross-couplings in organic synthesis Optimized geometries from B3LYP/BS1 calculations

3. “Future” Work Finish isotopic substitutions for IZnCH 3 I 66 ZnCH 3 IZn 13 CH 3 IZnCD 3 Columbus 2013 IZnCH 3 Summary Measured I 64 ZnCH 3 and I 64 ZnCH 3 (v=1) Determined preliminary IZnCH 3 structure Provided further evidence of zinc insertion ? IZnCH 3 HZnCH 3

4. Millimeter-Wave Direct Absorption Spectrometer Phase-locked Gun oscillators in combination with Schottky diode multipliers (65- 750GHz) Double-pass stainless steel chamber Gaussian beam optics InSb bolometer ~4K liquid He Phase sensitive detection

5. Molecular Production Scheme CH 3 I CD 3 I 13 CH 3 I Ar (carrier gas) Stabilizes discharge discharge electrode ~ 1-2 mTorr CH 3 I ~ 15 mTorr Ar(g) ~ 0.060 A (460 V)

6. 1357911 IZnCH 3 Isotopologues: K Components Champaign, We Have a Problem

7. IZnCH 3 Isotopologues: K Components Frequency (MHz)

8. Table of Frequencies Zn natural abundances: 64 Zn: 66 Zn = 49%: 28% -5 – 9 transitions between 256 – 293 GHz -K = 0 – 6 I 64 ZnCH 3 (v = 0)I 64 ZnCH 3 (v = 1)I 66 ZnCH 3 I 64 ZnCD 3 I 64 Zn 13 CH 3 J′←J″Kν obs ν obs-calc ν obs ν obs-calc ν obs ν obs-calc ν obs ν obs-calc ν obs ν obs-calc 116 1150272768.9110.006 270538.9790.001 116 1151272766.2470.002 270536.329-0.019 116 1152272758.2800.016 270528.4810.023 116 1153272744.9860.023 270515.3120.004 116 1154272726.325-0.016 270496.9280.031 116 1155272702.394-0.005 270473.192-0.035 116 1156272673.133-0.003 270444.3150.018 125 1240 293105.0620.003 268240.5940.007286748.1300.009 125 1241 293102.189-0.027 268238.5490.020286745.381-0.021 125 1242 293093.652-0.035 268232.3680.014286737.228-0.016 125 1243 268222.1090.045286723.633-0.014 125 1244 293059.553-0.019 268207.6880.030 125 1245 293033.936-0.049 125 1246 293002.7340.022 268166.5080.010

9. Spectroscopic Constants (MHz) a a Quoted errors are 3σ. I 64 ZnCH 3 (v = 0)I 64 ZnCH 3 (v = 1)I 66 ZnCH 3 I 64 ZnCD 3 I 64 Zn 13 CH 3 B1178.8444(10)1176.03988(98)1169.1951(24)1075.8051(17)1150.4001(16) DJDJ 0.000115797(40)0.000115829(34)0.000114404(88)0.000090970(51)0.000109043(51) D JK 0.011823(57)0.011746(55)0.01161(11)0.008554(93)0.010877(24) H JK 13.2(2.2)x10 -9 12.0(1.9) x10 -9 10.2(4.2) x10 -9 10.3(2.8) x10 -9 … rms0.0230.0280.0250.0320.035 SPFIT → Problems fitting with J > 99 SYMF → G. Cazzoli and Z. Kisiel, J. Mol. Spectrosc. 159, 96-102 (1993)

10. Molecular Structures of IZnCH 3 and Related Species Moleculer XM (Å)r MC (Å)r CH (Å) ∠ M-C-H (°) ∠ H-C-H (°) Method IZnCH 3 2.4076(2)1.9201(2)1.105(9)110.2(5)108.7(5)r0r0 2.44711.93931.0904110.192108.741B3PW91/6-311G++(3df,2p)/LanL2DZ 2.46061.95181.0892110.041108.895B3LYP/6-311G++(3df,2p)/LanL2DZ 2.45081.93831.0904110.201108.731B3PW91/6-311G++(3df,2p)/DGDZVP 2.46891.95051.0892110.031108.906B3LYP/6-311G++(3df,2p)/DGDZVP ZnCH 3 2.001 (7)1.105 a 109.73 a 109.21 a r0r0 HZnCH 3 1.5209(1)1.9281(2)1.140(9)110.2(3)108.7(3)r0r0 a fixed parameters

11. IZnCH 3 Structure Comparisons 2.437 Å 1.914 Å 111.1 ° 107.8 ° B3LYP/6-311G*/LanL2DZ J. Org. Chem. 73, 2008, 3680 - 3688 r 0 structure

12. 1) Zn + ICH 3 → ZnCH 3 + I → IZnCH 3 No ZnCH 3 (X 2 A 1 ) 2) Zn + ICH 3 → ZnI + CH 3 → IZnCH 3 No ZnI (X 2 Σ + ) 3) Zn + ICH 3 → IZnCH 3 IZnCH 3 formed by Zn insertion into the C-I bond of CH 3 I IZnCH 3 Formation: Evidence of Zinc Insertion

13. Future Work FTMW IZnCH 3 I 67 ZnCH 3 ZnI (X 2 Σ + ) Search for ZnI in progress Difficulties with iodine Summary Measured I 66 ZnCH 3, IZnCD 3, and I 64 Zn 13 CH 3 Determined IZnCH 3 structure Provided further evidence of zinc insertion

14. Acknowledgements  Prof. Lucy Ziurys  Ziurys Group  DeWayne Halfen, Gilles Adande, Jessica Edwards, Jie Min, Julie Anderson, Debbie Schmidt, Curtis Jorgensen  Prof. Phil Sheridan  Justin Young  Funding  NSF  NASA

15. While Searching for ZnCH 3 … 135 272.740 272.840 Frequency (GHz) 275.055 275.155 Frequency (GHz) Weak symmetric top pattern

16. Champaign, We Have a Problem CH 3 I lines – everywhere

17. What is it? -Must be symmetric top (1:3:5:7) --No doublets -Rules out ZnCH 3 -Contains Zn -Out of Zn → lines disappear -Rules out ICH 3 -Contains –CH 3 moiety -K a = 0, 3, 6 → Fermi-Dirac nuclear spin statistics -B value ~ 1.2 GHz -ZnCH 3 (~ 9.3 GHz) -Heavy atom attached? -Iodine is available from CH 3 I -Substitute Sn(CH 3 ) 4 for CH 3 I to determine iodine dependence -Lines disappear -IZnCH 3 = consistent with experimental observations Zn excited state (4s4p) can insert into C-H and C-C bonds* * Breckenridge, W. H. J. Phys. Chem. 1996, 100, 148480-14855

18. Optimized IZnCH 3 Conditions Ka=Ka= 0 1 2 3 45 6 Symmetric top pattern ! 272.660 272.770 Frequency (GHz) J = 116 ← 115

19. 272.740 272.840 Frequency (GHz) 272.065 272.175 Frequency (GHz) I 64 ZnCH 3 : J = 116 ←115 I 66 ZnCH 3 : J = 116 ←115 012 3 01 2 3 K a components 64 Zn: 66 Zn = 49%: 28%

20. No previous experimental/theoretical work C 3v symmetry Assumed linear I-Zn-C backbone IZnCH 3 (X 1 A 1 ) Previous X-Zn-Y Molecules HZnCN (X 1 Σ + ) ( J. Chem. Phys., 034309 (2009)) Synthesized using (CH 3 ) 2 Zn and (CN) 2 gas HZnCl (X 1 Σ + ) ( J. Mol. Spectrosc., 257, 128 (2009)) Synthesized using Cl 2 and H 2 gas HZnCH 3 (X 1 A 1 ) (J. Am. Chem. Soc. 132, 17186 (2010)) Synthesized using Zn and CH 4 gas – Broida-type oven Synthesized using Zn(CH 3 ) 2 and Ar – Source Modulation HMCH 3 species ‘Zn, Ca, Mg will not insert into CH 4 ’ J. Organomet. Chem. 2006, 691, 4341-4349.