This document contains the agenda for Shobeir K. S. Mazinani's PhD dissertation oral defense at the School of Molecular Sciences. The defense will take place on November 13th and focus on Mazinani's research using molecular models and descriptors to study electron transport in molecular junctions and electrochemical electron transfer. The document outlines Mazinani's work applying theoretical approaches like the Landauer formula and polarizability calculations to examine conductance in examples like halo-benzenes and hydrogen bonds. It also summarizes Mazinani's studies of a nickel phosphine catalyst for hydrogen production and contributions of ligand geometry to its redox properties.

1. PhD Dissertation Oral Defense Shobeir K. S. Mazinani
School of Molecular Sciences
Shobeir K. S. Mazinani
Molecular Models for Conductance in Junctions
and Electrochemical Electron Transfer.
Dr. Vladimiro Mujica (Co-Chair)
Dr. Tarakeshwar Pilarisetty (Co-Chair)
Dr. C. Austen Angell
Dr. Anne K. Jones
Fri., Nov. 13, 10:15AM, PSC 112

2. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesOutline
Assessing the Quality of Electron Transport Through Weak Links
and Hydrogen Bond.
In Conductance. {Molecular Electronics}
Electrode Reactions and Catalysis in Confined Spaces.
Using molecular descriptors in three examples of
Electron transfer/transport:

3. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesRatner & Aviram
Molecular Rectifier
1974
𝐷 − 𝜎 − 𝐴

4. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesBut 41 years later
There is not a single commercial device!
Intel is fabricating a 14nm node.
Go to 10 nm in 2017!
“I see Moore’s law dying here”

5. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Choi, Yongki, et al. "Single-molecule lysozyme dynamics monitored by an electronic circuit." Science 335.6066 (2012): 319-324.
Credit: Biodesign Institute at ASU
The Opportunity
Recognition and Sensors

6. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesTheory
𝐼 𝑉 =
2 𝑒
ℎ 𝜇 𝐿
𝜇 𝑅
𝑑𝐸 𝑇 𝐸 𝑓𝑅(𝐸) − 𝑓𝐿(𝐸)
Landauer Formula
𝑔 𝑉 =
𝜕𝐼
𝜕𝑉
Conductance

7. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
hormones by Nathalie Dumont from the Noun Project
Chemical Space is BIG!
1060
Polarizability as a molecular descriptor.
QM-Descriptors

8. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesPolarizability
𝜇 = 𝛼 𝐸
Laser
Frequency
(𝛼 𝜌𝜎) 𝑓𝑖=
2𝜋
ℎ 𝑛≠𝑖,𝑓
< 𝑓|𝜇 𝜌|𝑛 >< 𝑛|𝜇 𝜎|𝑖 >
𝜔 𝑛𝑖 − 𝜔 𝐿 − 𝒊 𝛾𝑛′
Inverse of the
life time of
excited state
Kramers-Dirac-Heisenberg

9. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesSet Up
ElectrodeBridge
Anchoring
Group
Linker
Molecule Acceptor
Electrode
Donor

10. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesHalo-benzenes
𝑔0 =
2𝑒2
ℎ
= 7.75 × 10−5
𝑆
Substituent Effect
Venkataraman, L.; Park, Y. S.; Whalley, A. C.; Nuckolls, C.; Hybertsen, M. S.; Steigerwald, M. L. Nano Lett. 2007, 7, 502–506.

11. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesTrend?
1. F
2. Cl
3. CHF2
4. OCH3
5. SH
6. NO2
7. CH2Cl
8. CCl3

12. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesHOMO-LUMO GAP
Hypothesis:
HOMO- LUMO gap is an estimate of the tunneling barrier.

13. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesHOMO-LUMO GAP
1. F
2. Cl
3. CHF2
4. OCH3
5. SH
6. NO2
7. CH2Cl
8. CCl3

14. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesThiophene-Furan Motif

15. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Amine-Motif
Diamine Bipyridine

16. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesObservations
There is a robust correlation between
Conductance and Polarizability
Higher Polarizability lower conductance
It holds for families of Molecules.
Created by David Washcusch from the Noun Project

17. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesEXPLANATION?
Barrier Model of Conductance
Simmons’ model
𝜙 = 𝜙0 − 𝑞𝑉
𝑠1+𝑠2
2𝑥
− 𝐵
1
𝜖 𝑟
Dielectric Constant
Barrier height
Simmons, J. G. J. Appl. Phys. 1963, 34, 1793.
𝐵 =
1.15𝜆𝑥
Δ𝑠
𝑙𝑛
𝑠2(𝑥 − 𝑠1)
𝑠1(𝑥 − 𝑠2)

18. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesClausius-Mossotti
Octavio Fabrizio Mossotti (Institute and Museum of the History of Science / Eurofoto, http://brunelleschi.imss.fi.it/itineraries/image/img33988.html
Gravity, By Joerg Kliemann, The noun project
𝜖 𝑟 =
𝜖0 + 2𝛾𝛼
𝜖0 − 𝛾𝛼
I. Polarization, proportional to the field.
II. Polarizable molecules, Isotropic.
III.Short range interactions, ignored.
Surprise: Seems to be valid in the nanoscopic/molecular regime !!

19. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
𝜙 = 𝜙0 − 𝑞𝑉
𝑠1 + 𝑠2
2𝑥
− 𝐵
𝜖0 + 2𝛾𝛼
𝜖0 − 𝛾𝛼
−1

20. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Diamine Bipyridine

21. Molecular Junction Sensors
PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Xiao, Xiaoyin, Bingqian Xu, and Nongjian Tao. "Conductance titration of single-peptide molecules." Journal of the American Chemical Society 126.17 (2004): 5370-5371.

22. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Nishino, Tomoaki, Nobuhiko Hayashi, and Phuc T. Bui. "Direct measurement of electron transfer through a hydrogen bond between single molecules." Journal of the American Chemical Society 135.12 (2013): 4592-4595.
Hydrogen Bond

23. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
NH…O< NH…N < OH…O < OH…N
Electronic Transport across Hydrogen Bonds in Organic Electronics, R. V. Meidanshahi, S. K. S. Mazinani, V. Mujica, and P. Tarakeshwar, Int. J. Nanotechnol. Volume 12, Numbers 3-4 (2015).
Hydrogen Bond
Highly Neglected!

24. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Electronic Transport across Hydrogen Bonds in Organic Electronics, R. V. Meidanshahi, S. K. S. Mazinani, V. Mujica, and P. Tarakeshwar, Int. J. Nanotechnol. Volume 12, Numbers 3-4 (2015).
Hydrogen Bond

25. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesHydrogen Production
Bio-Inspired

26. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesHydrogen Production
Ni-Fe
dppf: Sterically Prohibitive
bdt: Non-innocent Ligand
Gan, Lu, et al. "A Nickel Phosphine Complex as a Fast and Efficient Hydrogen Production Catalyst." Journal of the American Chemical Society 137.3 (2015): 1109-1115.

27. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesGeometry
1: Ni-dppf-bdt
2: Ni-dppe-bdt
21
E1/2=-1.280 V
E1/2=-0.518 V

28. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesECEC

29. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesContribution from Fe?

30. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesReduction of Ni
Structural Changes

31. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesWhich Site?
31 is more stable than 32:
3.6 kcal/mol
41 is more stable than 42:
15.3 kcal/mol

32. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesTransition State
TS: pseudo-octahedral
Dihydral angle changes:
40 degrees!
Ni-S and Ni-P bonds
changed by 0.1 and 0.15 Å

33. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesObservations
Acts as a mononuclear Ni complex.
No bonding interaction between Ni and Fe.
The bite Angle and rigidity of dppf ligand are more relevant.
Ligand enforces certain geometry on Ni
Modifies electronic structure.
Modifies redox properties.
Created by David Washcusch from the Noun Project

34. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesAcknowledgement

35. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesTHANK YOU!

36. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular SciencesAddition

37. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences

38. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Obtained on November 2015 from: http://betanews.com/2013/10/15/breaking-moores-law/
Moore’s Law
Number of transistors per chip doubles
every 2 years!
1965
Faster and Smaller.

39. PhD Oral Defense Shobeir K. S. Mazinani
School of
Molecular Sciences
Obtained on November 2015 from: http://muonray.blogspot.com/2012/12/richard-feynman-theres-plenty-of-room.html
Richard Feynman
Top to Bottom
1959
Bottom to Top