Term
Alkyl, and occasionally aryl (aromatic) functions are represented by the R-
Methyl: CH3–
Ethyl: CH3CH2–
Propyl: CH3CH2CH2–
Isopropyl: (CH3)2CH–
Phenyl: C6H5–
etc. |
|
Definition
|
|
Term
|
Definition
| M+2 peak is nearly as tall as m peak |
|
|
Term
|
Definition
| M+2 peak is 1/3 of the size of M+ peak |
|
|
Term
|
Definition
| has an odd # for their M+ peaks |
|
|
Term
|
Definition
high frequency
large wave#
short wave lengths |
|
|
Term
|
Definition
greater the charge in the dipole moment, more intense the absorption
-more polar the bond, the more intense it is |
|
|
Term
|
Definition
-cant determine structure alone
-some signals are ambiguous
-if there is an absence of a signal, thats definite proof that the function roups is absent
-look at the literature value of the compound to confirm or vice versa |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| acid strength: down group |
|
Definition
| larger size differnce, weaker bond |
|
|
Term
| acid strength: across row |
|
Definition
| greater electronegativity, more polorized bond |
|
|
Term
| acid strength: c-H vs C-O |
|
Definition
| conjugate base is stablized by inductive and resonance effects |
|
|
Term
| acid strength: molecular weight |
|
Definition
| conjugate base is better stablized by inductive effects |
|
|
Term
| stronger bases than -OH put in water |
|
Definition
leveling effect
-bases stronger than OH- will simply deprotonate water to form the weaker base OH- |
|
|
Term
|
Definition
| what is the main piece of information sought from analysis of a compound by low-resolution mass spectrometry? |
|
|
Term
|
Definition
| What is the main piece of information sought from analysis of a compound by high resolution mass spectometry? |
|
|
Term
| identification of functional groups |
|
Definition
| What is the main piece of information sought form analysis of a compound by infrared spectroscopy? |
|
|
Term
-hexane
has a higher molecular weight and more van der waals interactions |
|
Definition
| higher BP: hexane vs pentane? |
|
|
Term
-alcohol
can hydrogen bond to its neighbors |
|
Definition
| higher BP: ether vs alcohol |
|
|
Term
1. ion charges
2. higher molecular weight
3. has halogen |
|
Definition
|
|
Term
|
Definition
| most inportant factor for higher MP? |
|
|
Term
1. ion-ion, coulombic attraction
2. dipole-dipole attraction
3. hydrogen bond - typeof dipole-dipole
4. van der waals -transient dipole-dipole |
|
Definition
| explain 4 differnt types of bonds |
|
|
Term
| a gas chromotograph and a mass spectrometer |
|
Definition
| what two instruments are coupled together in a so-called GC-MS? |
|
|
Term
compounds with ane ven # of nitrogenn
(or O) have an even molecular mass
compounds with an odd # of nitrogems have an odd molecular mass |
|
Definition
| explain what the nitrogen rule is |
|
|
Term
| the stretch produces no charge in the dipole moment |
|
Definition
| why cant the symmetrical stretch of carbon dioxide produce a peak (absorption) in a normal IR spectrum? |
|
|
Term
H2O
has a greater propensity to donate a proton because the conjugate base (OH-) would be more stable than (NH2-) due to the more electronegative oxygen atom |
|
Definition
which one is the stronger acid and why?
H2O vs NH3 |
|
|
Term
CH3CF2COOH
has a greater propensity to donate a proton because the conjugate base is more stable as a result of the more effective (-) charge delocalization due to stronger induction thru the sigma bonds by the more proximal F atoms |
|
Definition
which one is the stronger acid?
F2CHCH2COOH vs CH3CF2COOH |
|
|
Term
HCl
has a greater propensity to donate a proton becaus the conjugate base (Cl-) would be more stable than (F-) due to Cl- being larger and the negative charge being dispersed over a larger volume |
|
Definition
which one is the stronger acid?
HF vs HCl |
|
|
Term
CH=-CH
has agreater propensity to donate a proton because the conjugate base is more stable as a result of the lone pair residing in an sp orbital (as opposed to an sp3 orbital) which has more s character (50%), so the lone pair is in a lower energy, closer to the nucleus |
|
Definition
which is the stronger acid?
CH3CH3 vs CH=-CH |
|
|
Term
| pie bonds and heteroatoms |
|
Definition
| in general, what are two structural features in organic compounds, any one of which, that give rise to so-called functional groups and useful reactivity? |
|
|
Term
| electromagnetic radiation |
|
Definition
| radient energy having dual properties of both waves anad particles |
|
|
Term
|
Definition
| particles of electromagnetic readiation |
|
|
Term
|
Definition
| each photon has a discrete amount of energy |
|
|
Term
|
Definition
| electrommagnetic radiation can be characterized by its: |
|
|
Term
|
Definition
| the distance form one point on a wave to the same point on an adjacent wave |
|
|
Term
|
Definition
| the number of waves passing per unit of time, hertz |
|
|
Term
|
Definition
t/F?
for absorption ot occur, the energy of the photon must match the difference between two energy states in a molecule |
|
|
Term
|
Definition
| the energy source used in IR spectroscopy |
|
|
Term
|
Definition
t/f?
absorption of IR light causes changes in the vibrational motions of a molecule |
|
|
Term
|
Definition
t/f?
IR spectroscopy distinguishes between the different kinds of bonds in a molecule, so it is possible to determine the functional groups present |
|
|
Term
1. light passes through a sample
3. frequencies that match the vibrational frequencies are absorbed,and the remaining light is transmitted to a detector
3. an "IR spectrum is a plot of the amount of transmitted light versus its wavenumber |
|
Definition
|
|
Term
|
Definition
| that all the light shone on a sample is transmitted and none is absorbed |
|
|
Term
|
Definition
| that none of the light shone on the sample is transmitted and all is absorbed |
|
|
Term
|
Definition
t/f?
stronger bonds vibrate at a higher frequency, so they absorb at higher wavenumbers |
|
|
Term
|
Definition
| bonds with lighter atoms vibrate at higher frequency, so they absorb at higher wavenumbers |
|
|
Term
|
Definition
| the higher the percent s-character, the stronger the bond and the hgiher the wavenumber of absorption |
|
|
Term
|
Definition
| for a bond to absorb in the IR, there must be a change in dipole moment during the vibration |
|
|
Term
|
Definition
| symmetrical nonpolar bonds do not absorb in the IR |
|
|
Term
|
Definition
| IR spectroscopy is often used to determine the outcome of a chemical reaction |
|
|
Term
|
Definition
| i a mass spectrometer, a molecule is vaporized and ionized by bombardment with a beam ofhigh-energy electrons |
|
|
Term
|
Definition
| the electron beam ionizes the molecule by causing it to eject an electron |
|
|
Term
|
Definition
| when the elctron beam is ionized the molecule, the species that is formed is called? |
|
|
Term
|
Definition
| the mass of M+ represents the molecular weight of M |
|
|
Term
|
Definition
| because M is unstable, it decomposes to fomr fragments of radicaals and cations that have a lower molecular weight than M+ |
|
|
Term
|
Definition
| the mass spectrum analyzes the masses of cations, a plot of the amount of each cation versus its mass to charge ratio |
|
|
Term
|
Definition
| when the sample is injected into the GC, it is vaporized and swept by an inert gas through the column and components are usually seperated by boiling points |
|
|
