Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
Types of spectroscopy |
NMR- uses radio waves, based on positioning of carbon or hydrogen atoms. IR- uses infrared waves, tells position of functional groups. UV vis- uses uv and visible light. Tells presence of conjugated pi systems. |
|
|
nmr notes |
electrons shield protons from magnetic field. left is downfield, right is upfield. Downfield means highly unshielded by electrons. Upfield mean very shielded. Each peak is chemically equivalent hydrogens. Peaks get split by neighboring hydrogens. LEFT EQUALS UNSHIELDED!!!!!!! it is stripped of electrons. Cnmr is done with C13. |
|
|
What causes a leftward shift on nmr. |
a stripping of electrons causes by EWG's. protons get unshielded. |
|
|
Common shifts |
Aldehydes have a shift at 9.5 ppm. |
|
|
IR functional groups need to know. |
Carbonyl, C=O at 1700 cm-1. OH, broad dip at 3200-3600. bonus- N-H is at 3300. Sharp peak. |
|
|
UV vis spec. |
30-40 nm increase for each aditonal conjugated double bond. and 5nm increase for each aditional alkyl group. |
|
|
Mass spec |
used to determine molecular weight. the molecular ion peak(parent peak) is the actual molecule minus one electron. it has the same weight. base peak is the largest peak. |
|
|
visible region of light |
400 to 700 nm |
|
|
PCR |
when copying. a single strand for 20 cycles. it goes 2 to the 20th. for n strands, and x cycles. it is 2n to the xth. |
|
|
distillation |
only good for compounds with bp diffring by more than 20 degrees c. |
|
|
crystaliation |
not too effective. pure things way more likely to crystallize. like glacier ice. |
|
|
POLAR PLATE |
the polar compound will stick to the polar plate, and thus have lower rf. |
|
|
blots |
southern-dna, norhtern, rna, western-peptides. protiens are not seperated by pores, they are too large. instead by isolecric points and size/charge stuff. detergent coats and makes them negative, larger means mroe negative and move faster. |
