How does molecular properties, chemical properties and observable effects, effect each other?
Molecular prop. determine —> Chemical prop. which determine —> observable effects
Name 9 molecular properties.
- Size (big: lower volability, not easily vaporized —> less toxic)
- Form
- Electron distribution (e-clouds)
- Electron mobility (how easy the e- in the molecule can move around)
- Dipole moment (tells you how polar the molecule/bond is. C-Cl: Cl higher e-neg. —> pulls e-)
- Polarisability (defines how easy the e-clouds of a molecule can be pulled away by an external electric field.
- C-SH and C-CL: not strong e-neg, doesn’t bind e- very strongly—> high polarisability
- C-O and C-F: binds the e- stronger —> low polarisabillity)) - Charge (+/-)
- Electrophilicity (likes e-, will accept e-)
- Nucleophilicity (likes nucleus, e-rich, donates e-)
Name 9 chemical properties.
- Volatility (how easily a substance can vaporize)
- Solubility (tells lipophilicity and hydrophilicity)
- Reactivity (how molecules reacts in different environments)
- Lipophilicity (very lipophilic molecules can go to our brain because our brain is fatty)
- Hydrophilicity (water loving)
- Surface activity (the property possessed by some solid substances that can influence the surface tension of liquids, like making oil and water mix)
- Excitability (absorb light)
- Acidity/basicity (if the chemical is an acid or base)
- Absorption/adsorption (abs: a sponge —> goes inside, ads: get something on the surface)
- abs: molecules goes inside and over to the next phase
- ads: molecules stick to the surface of the other phase
Name 8 observable effects.
- Irritating
- Carcinogenic (cancer)
- Accumulating (if a stable chemical doesn’t want to metabolize, and it’s very hydrophobic+lipophilic —> will be stored in our bodies/brains —> will not go anywhere —> will accumulate)
- Persistent (resist changes in nature, like benzene with a lot of Cl/F are usually very resitant/persistent in nature, will stay in the environment without changes)
- Allergenic (some molecules can cause allergies)
- Intoxicating (make you feel dizzy, drunk)
- Burning
- Explosive
Which one is dangerous to humans: electrophiles or nucleophiles?
Electrophiles are always dangerous!
Nucleophiles aren’t dangerous.
Can we have both electrophiles and nucleophiles in our body? Why/why not?
No we can’t. If we had both they would react and we don’t want reactions. Nature constructed our bodies with nucleophiles so we are weak nucleophiles. H20, proteins (amino groups, OH, SH), DNA are all nucleophiles —> we usually do not want electrophiles.
What three chemical properties will effect the toxicological aspect?
Volatility, solubility and reactivity
What determines a molecules volatility?
Size (large: low volatility) and intermolecular forces (strong intra. mole. forces: high boiling point, lower volatility)
What is the best way to measure a morlcules volatility?
The boiling point. High boiling point —> low volatility
Name 4 intermolecular forces. Also mention if they are strong or not.
- Ionic forces (strong)
- Hydrogen bonds (strong)
- Dipole interactions - with polar groups (not that strong, but much stronger than van der Waals)
- van der Waals forces (if a molecules doesnt have any polar groups, like benzene, hexane, they will only have van der Waals forces)
How does the molecules shape matter?
More branches: lower boiling point (because the surface area differs)
They could have the same molecular weight and look almost the same except for one atom but the boiling points could differ a lot. This could depend on that one molecule has a higher dipole moment —> higher boiling point)
What does solubility tell us about a chemical?
It determines how a chemical us taken up by an organism and distributed in it
In what kind of “material” are lipophilic, or hydrophobic, compounds soluble in?
They are soluble in fat
In what kind of “material” are hydrophilic, or lipophobic, compounds soluble in?
They are soluble in water
A pratical measure for solubility is P (or logP). What does it stand for?
LogP is a scale of solubility between two solvents: water and octanol. A negative logP value indicates preferential solubility in water and a positive logP value indicates an affinity for octanol.
- lower: hydrophilic
- higher: more hydrophobic
Say if the following are hydrophobic or hydrophilic:
OH?
C?
COOH?
If a molecule has 5 OH and 6 C, is it hydrophobic or hydrophilic?
OH: hydrophilic
C: hydrophobic
COOH: hydrophilic
The molecule is highly hydrophilic, logP=-3.3
What logP-value does a molecule need to have to be used as a medication?
A logP-value between 1-5
What 7 properties decide a molecule’s reactivity?
- Free radicals
- Acids and bases
- Oxidative and reductive agents
- Explosives
- Photo excitable agents
- Ligands (non-covalent binding)
- Electrophiles (covalent binding)
What are free radicals and how do they react with other molecules?
Radicals has a single unpaired e-. Radicals normally abstract hydrogen atoms or add to unsaturations.
Is a free radical more or less reactive if it has resonance?
It’s less reactive. The molecule is stabilized through resonance.
In a radical reaction, what is often the product?
A new radical is often produced.
Is the molecule a acid or a base if it can donate a proton? And if it can accept a proton?
Donate proton: acid
Accept proton: base
What is an oxidative agent? Name a few oxidizing agents.
It’s a substance that has the ability to oxidize other substances - in other words, to accept their electrons. Common oxidizing agents are oxygen, hydrogen peroxide and the halogens.
What is a reductive agent? Name a few reductive agents.
It’s a substance that has the ability to reduce other substances - in other words, it can donate its electrons. Common reductive agents are earth metals, formic acid (myrsyra), oxalic acid (oxalsyra) and sulfite compounds.
