Transcript What Does a Chemist Do?

Luis Avila
[email protected]
Room: Chandler 455
Phone #: (212)854-8587
1
What
Does
a Chemist Do?
What
is Chemistry?
“Take white lead, one part, and any glass
youthe
choose,
two parts,
fuse together
• Studies
atomic composition
and structural
features ofin a
substances.
crucible and then pour the mixture. To
this crystal
add
the urine
an ass and
• Investigates
the varied
interactions
amongof
substances
after forty days you will find emeralds”
• Utilizes natural substances and creates artificial ones.
• Comprehends
theThe
complex
chemistry
living
organisms.
Stillman, J. M.
story of Alchemy
andof
Early
Modern
Chemistry;
Dover: New York 1960, p. 160.
• Provides a molecular interpretation of health and disease.
2
How Does She/He do it?
Main Divisions of Chemistry
Organic Chemistry
Inorganic Chemistry
Materials Chemistry
Physical Chemistry
Analytical Chemistry
Industrial Chemistry
(Chemical Engineering
and Applied Chemistry)
Environmental Chemistry
Forensic Chemistry
Biochemistry
3
What is Organic Chemistry?
Largest area of specialization among the various fields of chemistry
Synthetic Organic Chemistry
 Pharmaceutical Chemistry
 Polymer Chemistry
 Dye and Textile Chemistry
 Pulp and Paper Chemistry
 Agricultural Chemistry
 Formulation Chemistry (paint, food, petroleum products, adhesives, etc.)
Physical Organic Chemistry
Correlates the physical and chemical properties of
compounds with their structural features.
4
We are interested in the
multistep synthesis of
natural products, as well
as the development of new
methodology, particularly
to address problems of
regio- or stereocontrol. At
present (1999), we are
working on problems
suggested by structures
such as those of germine,
taxol, cardenolides and
codeine
Synthetic Organic Chemist:
Professor Gilbert Stork
5
2-acetylnerifolin (class Cardenolide)
Natural Product with Antitumor Activity
Taxol
Natural Product with Antitumor Activity6
Synthetic Organic Chemist /
Bioorganic Chemist:
Professor Samuel Danishefsky
Among our areas of current interest
in the anticancer field are
epothilone and eleutherobin. While
structurally diverse, these two
compounds seem to function by a
taxol-like mechanism in their ability
to inhibit microtubule disassembly.
Several projects are addressed to
goal systems with immunochemical
implications. Here we are
particularly concerned with the
construction of a carbohydratebased tumor antigen vaccine.
7
We deal with structural aspects of bioactive compounds
and elucidation of their mode of action.
In most cases this involves
investigating the interaction
of small molecules with their
biopolymeric receptors. The
recent dramatic advancement
in isolation, purification and
microspectroscopic methods
has made it possible for
chemists to become involved
in such studies on a
molecular structural basis
Natural Products Chemist :
Professor Koji Nakanishi
8
We view the photon as a reagent for initiating photoreactions and as
a product of the deactivation of electronically excited molecules.
Our group is developing a novel field
termed "supramolecular"
photochemistry, or photochemistry
beyond the conventional intellectual and
scientific constraints implied by the term
"molecule". In supramolecular
processes non-covalent bonds between
molecules play a role analogous to that
of covalent bonds between atoms.
Physical Organic Chemist / Photochemist
Material Chemist:
Professor Nicholas Turro
9
What is Inorganic Chemistry?
Deals with the properties of elements ranging from metals
to non metals
• Organometallic Chemistry
• Bioinorganic Chemistry
• Ceramics and Glass
• Semiconductors
10
We have a continuing interest in exploring unusual artifacts
resulting from X-ray diffraction experiments (e.g. "bond
stretch" isomerism)
One of our interests is concerned
with compounds with metal-ligand
multiple bonds, which are species
of considerable current interest in
terms of both their bonding and
reactivity.
Organometallic Chemist / X-ray Spectroscopist:
Professor Gerard Parkin
11
In our major effort we are trying to prepare artificial enzymes
that can imitate the function of natural enzymes.
Bio-organic Chemist :
Professor Ronald Breslow
A related study involves the
synthesis of mimics of
antibodies or of biological
receptor sites, constructing
molecules that will bind to
polypeptides with sequence
selectivity in water, using
mainly hydrophobic
interactions. These could
be very useful in modulating
the activity of peptide
hormones, for instance.
12
What is Physical Chemistry?
Measures, correlates, and explains the quantitative aspects of chemical
processes
 Theoretical Chemistry
Devoted to Quantum and Statistical Mechanics.
Theoretical chemists use computers to help them solve complicated
mathematical equations that simulate specific chemical processes.
 Chemical Thermodynamics
Deals with the relationship between heat, work, temperature,
and energy of Chemical systems.
 Chemical Kinetics
Seeks to measure and understand the rates of chemical
reactions.
13
Physical Chemistry
 Electrochemistry
Investigates the interrelationship between electric current and chemical change.
 Photochemistry, Spectroscopy
Uses radiation energy to probe and induce change within matter.
 Surface Chemistry
Examines the properties of chemical surfaces, using instruments that can
provide a chemical profile of such surfaces.
14
My research is concerned with structural and dynamic
processes in condensed phase systems and biomacromolecular
systems.
Because the systems studied are
often complex many-body
systems, it is necessary to utilize
the powerful analytical methods
of statistical mechanics as well as
state-of-the-art methods of
computer simulation involving
molecular dynamics and Monte
Carlo techniques.
Theoretical Chemist: Professor Bruce Berne
15
Materials Chemist:
Professor Louis Brus
My research is materials,
surfaces and nanocrystals,
especially in relation to
optical and electronic
properties. This work can
include theoretical
modeling, experimental
chemical physics, and
synthetic chemistry. We try
to understand the evolution
of solid state properties from
molecular properties, and to
create new materials with
nanoscale structure by both
kinetic and thermodynamic
self-assembly methods. 16
Materials Chemist /
Near Field Microscopist
Professor David Adams
Our research program involves the
design, synthesis, and detailed
physical investigation of novel
molecular and nanoparticle materials
which display unique self-organized
hierarchical structures and specific
optical, electronic, and/or magnetic
properties. Emphasis is placed on
materials with potential applications
in light-emitting devices, optical
memory devices, molecular level and
single particle level switching devices,
and chemosensory devices. Our
research is necessarily
interdisciplinary where students and
post-doctoral researchers are exposed
to modern aspects of inorganic,
physical, and materials chemistry.
17
Experimental Physical Chemist / Surface Chemist
Professor George Flynn
We investigate molecular
collisions that lead either to
chemical reaction or to the
exchange of energy between
molecules. In particular, we
have developed the infrared
diode laser absorption probe
technique to investigate
collisions between molecules.
We also study the structure of molecules
adsorbed on surfaces by using the
Scanning Tunneling Microscope (STM).
18
What is Analytical Chemistry?
QUALITATIVE ANALYSIS deals with the detection of elements or compounds
(analytes) in different materials.
QUANTITATIVE ANALYSIS refers to the measurement of the actual amounts of
the analyte present in the material investigated.
 Chemical and Biochemical Methods
•Gravimetry
•Titrimetric Analysis
•Enzymic Analysis
•Inmunochemical Analysis
19
Analytical Chemistry
 Atomic and Molecular Spectroscopic Methods
•Nuclear Magnetic Resonance (NMR)
•Electron Spin Resonance (ESR)
•Mass Spectrometry (MS)
•Vibrational Spectroscopy (IR, RAMAN)
•X-Ray Fluorescence Analysis (XPS)
•Electronic Spectroscopy (UV, VIS, Luminiscence)
•Atomic Spectroscopy (AA, ICP)
•Rotational Spectroscopy (Microwave, FIR)
20
Analytical Chemistry
• Chromatographic Methods (Partition equilibrium)
•Gas Chromatography (GC)
•High Performance Liquid Chromatography (HPLC)
•Gel Permeation Chromatography (GPC)
•Thin Layer Chromatography (TLC)
•Ion Chromatography
21
Analytical Chemistry
 Thermal Methods
•Thermogravimetry (TG)
•Differential Thermal Analysis (DTA)
•Differential Scanning Calorimetry (DSC)
•Thermomechanic Analysis (TMA)
 Electrochemical Methods
•Electrogravimetry
•Electrophoresis
•Conductimetry,Potentiometry
•Polarography
•Voltammetry
22
We study enzyme mechanisms using NMR. A variety of experiments
allow us to probe structural details,dynamics or chemical details such
as protonation states.
In photosynthetic reaction
centers, light energy is
converted to chemical
potential energy through
long-range electron transfer
events. A wealth of
crystallographic, mutagenic,
and spectroscopic work on
these centers still leaves
important mechanistic
questions unanswered.
Biophysical Chemist / NMR Spectroscopist:
Professor Ann McDermott
23
Our research interests center on the development of selection
strategies for identifying enzymes from large pools of proteins.
This research is interdisciplinary,
bringing together the techniques
of small-molecule synthesis,
molecular and cellular biology,
computer modeling, and
mechanistic enzymology and
structural biology. The need for
efficient catalysts is fundamental.
Biological catalysts drive cellular
processes, and the chemical
industry relies on catalysts for the
synthesis of compounds ranging
Molecular Biologist / Organic Chemist: from pharmaceuticals to
materials.
Professor Virginia Cornish
24
The Tools of the Trade
1
H
2
He
3 Be
4
Li
5 C
6 N
7 O
8
B
9 Ne
10
F
11 Mg
12
Na
13 14
18
Al
Si 15
P 16
S 17
Cl Ar
19
20 Sc
21 22
24 Mn
25 Fe
26 Co
27 Ni
28 Cu
29 Zn
30 Ga
31 Ge
32 As
33 Se
34 Br
35 Kr
36
K Ca
Ti 23
V Cr
37 38
41 Mo
42 Tc
43 Ru
44 Rh
45 Pd
46 Ag
47 Cd
48 49
50 Sb
51 Te
52 53
54
Rb
Sr 39
Y 40
Zr Nb
In Sn
I Xe
55 Ba
56 La
57 Hf
72 Ta
73 74
75 Os
76 77
79 Hg
80 Tl
8l Pb
82 83
84 At
85 Rn
86
Cs
W Re
Ir 78
Pt Au
Bi Po
87
88 Ac
89 104
Fr Ra
Rf 105
Ha 106
Sg 107
Bh 108
Hs 109
Mt
58 59
60 Pm
61 Sm
62 Eu
63 Gd
64 Tb
65 Dy
66 Ho
69 Yb
71
67 68
70 Lu
Ce
Pr Nd
Er Tmi
90 Pa
91 92
93 Pu
94 Am
95 Cm
96 Bk
97 Cf
98 Es
99 100
Th
U Np
Md 102
Lr
Fm 101
No 103
Periodic Table of the Elements
25
Interesting Applications
The KSC-ALS Breadboard Project
• Humans take in oxygen, food and water, and expel carbon
dioxide and organic waste. Plants utilize carbon dioxide,
produce food, release oxygen, and purify water. Inedible plant
material and human waste are degraded by microorganisms to
recycle nutrients for plants in a process termed resource
recovery.
26
When humans establish permanent bases on the Lunar surface or
travel to Space for exploration, they need to develop systems to:
• produce food
• purify their water supply and
• create oxygen from the carbon dioxide they expel.
Physico-chemical processes can perform the two latter tasks,
but only biological processes can perform all three.
27
• A life support system that would perform these regenerative
functions, whether strictly by biological means or by a
combination of biological and physical-chemical methods, has
been called a Controlled Ecological Life Support System
(CELSS).
• Biological systems utilize plants and microorganisms
to perform these life support tasks in a process termed
bioregeneration.
28
A CELSS is a tightly controlled system, using crops to perform life
support functions, under the restrictions of minimizing volume,
29
mass, energy, and labor.
A career alternative for chemists, a multidisciplinary arena to
prove the role of Chemistry as a "central science".
30