IN PURSUIT OF A TRANS -CHELATING DIPHOSPHINE LIGAND

1. Jacqueline Dragon; Samuel Flanzman; Johann Frias; Michael Gao; JinOhJeong; Angela Jin; Meeki Lad; Kevin Lin; YuzkiOey; Jessica Teipel; MathiniVaikunthan; Evan Zou Advisor: Dr. Mary-Ann Pearsall Assistant: Nicholas Chiappini NJGSS 2014 Drew University – Team Project 3 IN PURSUIT OF A TRANS-CHELATING DIPHOSPHINE LIGAND

2. INTRODUCTION Coordination Complexes B C e- M e- A Some Ligand • Organometallic Complexes • Useful as catalysts • Possess other unique properties Some Central Atom/Ion

3. INTRODUCTION Ligands and Chelation Halides Amines Diphosphine Carbonyls Phosphines Diphosphineschelate. That is, they can form coordinate covalent bonds in a complex at multiple sites.

4. INTRODUCTION The Experimental Goal Molybdenum Hexacarbonyl (Mo(CO)6) Mo(CO)4[(Ph2P)(CH2)n(PPh2)]

5. INTRODUCTION Experimental Obstacles Molybdenum hexacarbonyl reacts with phosphenes in multiple ways Monosubstitution Disubstitution Trisubstitution CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO Mo Mo Mo Mo Mo PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 PPh2 CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO Mo Mo(CO)6 [(Ph2P)(CH2) n (PPh2) ] CO CIS TRANS CO CO Mo CO CO

6. INTRODUCTION Activated Precursor Complexes CO How do we obtain a guaranteed trans product? CO CO Mo pip pip pip pip PPh2 PPh2 PPh2 pip pip PPh2 CO CO CO

7. INTRODUCTION LIGANDS Varying Hydrocarbon Length Longer hydrocarbon length = greater freedom of the diphosphine to chelate in a trans configuration

8. INTRODUCTION Expectations

9. EXPERIMENTAL Day 2: Mo(CO)4(pip)2 + [(Ph2P)(CH2)n(PPh2)] cis-Mo(CO)4 [(Ph2P)(CH2)n(PPh2)] + 2 pip Procedure and Rationale Heat Day 1: Mo(CO)6 + 2 pip Mo(CO)4(pip)2 + 2 CO Day 3: cis-Mo(CO)4 [(Ph2P)(CH2)n(PPh2)] trans-Mo(CO)4 [(Ph2P)(CH2)n(PPh2)] Heat Heat pip pip PPh2 PPh2 PPh2 PPh2 CO CO CO Mo CO CO CO CO

10. EXPERIMENTAL Collecting Data – IR Infrared Spectroscopy is a method of identifying chemical compounds by their characteristic dipole shifts and consequent % transmittance readings. This process was used at each experimental setup to confirm the presence of the desired compounds. Mo(CO)4 (pip)2 Mo(CO)6 cis- Mo(CO)4 [(Ph2P)(CH2)n(PPh2)] trans- Mo(CO)4 [(Ph2P)(CH2)n(PPh2)] Number of Distinct Dipole Shifts: 1 Expected Peaks: 1 Number of Distinct Dipole Shifts: 3 Expected Peaks: 3 Number of Distinct Dipole Shifts: 3 Expected Peaks: 3 Number of Distinct Dipole Shifts: 1 Expected Peaks: 1 pip pip

11. EXPERIMENTAL Collecting Data – Nuclear Magnetic Resonance Spectroscopy NMR is a method of spectroscopy that measures the alignment of phosphorus nuclei with a strong magnetic field, and in doing so, yields a graph that describes those atoms’ chemical environment.

12. RESULTS Control Group, Ligand PPh3 Mo(CO)4(PPh3)2 + Δ cis-Mo(CO)4(PPh3)2 IR NMR

13. RESULTS 1,12 Group, Ligand (PPh2)2(CH2)12 cis-Mo(CO)4[(Ph2P)(CH2)12(PPh2)] Mo(CO)4[(Ph2P)(CH2)12(PPh2)] + Δ IR NMR

14. RESULTS 1,8 Group, Ligand (PPh2)2(CH2)8 cis-Mo(CO)4[(Ph2P)(CH2)8(PPh2)] Mo(CO)4[(Ph2P)(CH2)8(PPh2)] + Δ IR NMR

15. RESULTS 1,4 Group, Ligand (PPh2)2(CH2)4 cis-Mo(CO)4[(Ph2P)(CH2)4(PPh2)] • Mo(CO)4 [(Ph2P)(CH2)4(PPh2)] + Δ IR NMR

16. RESULTS 1,5 Group, Ligand (PPh2)2(CH2)5 cis-Mo(CO)4[(Ph2P)(CH2)5(PPh2)] Mo(CO)4[(Ph2P)(CH2)5(PPh2)] + Δ IR NMR

17. RESULTS 1,6 Group, Ligand (PPh2)2(CH2)6 cis-Mo(CO)4[(Ph2P)(CH2)6(PPh2)] Mo(CO)4[(Ph2P)(CH2)6(PPh2)] + Δ IR NMR

18. ANALYSIS Discussion: Conclusions Increasing efficacy of cis-trans conversion

19. Ancillary Points

20. Acknowledgments • Dr. Mary-Ann Pearsall • NicholasChiappini • Independent College Fund of NJ/Johnson & Johnson • AT&T • Actavis Pharmaceuticals • Celgene • Novartis • Bayer Healthcare • Laura (NJGSS ’86) and John Overdeck • NJGSS Alumnae and Parents of Alumnae • Board of Overseers, New Jersey Governor’s Schools • State of New Jersey • Drew University