We need to draw the structure by using these spec graphs.
a) Electronegativity: An increase in electronegativity of the surrounding groups will decrease the electron density and increase the chemical shift value due to the deshielding.
If electropositive groups are present in molecules they increase the electron density on the adjacant atoms and decrease the chemical shift due to shielding
For example let's take an example :
CH3 - Cl , CH3 - H , CH3 - C2 H5
Cl is more electronegative than H and C will decrease the electron density on adjacent CH3 and inturn increasing CH3 protons chemical shift or making them deshielded. Whereas C2H5 shows inductive effect (+I) which increases the electron density on CH3 inturn decreases the chemical shift of the protons attached.
chemical shift values for CH3Cl protons will be higher than CH4 which will be in turn higher than CH3-C2H5
b) Magnetic anisotropy : When molecules having pi electrons such as benzene, alkenes, alkyne etc are placed in a magnetic field then these mobile pi electrons circulate around and produces a new magnetic field which has two regions shielded or deshielded.
Aromatic protons come under deshielded region.
c) Hydrogen bonding
Hydrogen bonding results from the presence of electronegative atoms
such as Fluorine, Nitrogen, Oxygen. Hydrogen bonds forms between F,
N, O with Hydrogen of F, N , O. The interactions thus forms leads
to deshielding to higher values of chemical shifts. This confirms
the presence of hydrogen bonding in the molecules.
Spilting
NMR spectra provides information about a the neighbouring hydrogens present for a particular hydrogen or group of equivalent hydrogens.
An NMR spectral peak will be split into N + 1 peaks where N = number of hydrogens on the adjacent atom.
Equivalent hydrogens means atoms that are completely interchangeable as to their role in the molecule. In the case of HNMR, the two Hydrogens which are on different atoms but have same chemical environment. They will show same chemical shift. As in the above question in benzene both protons which are labelled 'a' have same Chemical environment. Hence show same chemical shift.
Integration
It is the measurement of peak areas which corresponds to the amount of energy Absorbed or released by all nuclei participating in chemical shift during the nuclear spin flip. It also helps us to determine the ratio of hydrogens that correspond to the signal.
We need to draw the structure by using these spec graphs. Unknown number: 2129 Callam/Paul Chemistry...
Need help drawing the skeletal structure of the unknown compound
Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm HNMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants (values) are listed next to the peaks for some examples. For some spectra, an inset (grey box)...
Please provide possible chemical formula for this spectra!
Unknown number: 2055 Chemistry 2540 Spectroscopy Unknown - 25 points Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm 'H NMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants (/-values) are listed next to the peaks for...
Spectroscopy Unknown. The spectra and data provided were
obtained from a pure organic molecule.
For 1H NMR Spectra, the integral is given in number of
hydrogens (#H) or as a relative ratio. Important coupling constants
(J-values) are listed next to the peaks for some examples. For some
spectra, an inset (grey box) is also given showing a “zoom-in” on
an important part of the spectrum.
Unknown number: 1039 Callam/Paul Chemistry 2540 Spectroscopy Unknown - 25 points Information: Each spectra below...
Draw the skeletal structure of the unknown compound
Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm H NMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants (-values) are listed next to the peaks for some examples. For some spectra, an inset (grey box) is...
Draw the Skeletal Structure of the Unknown Compound.
Note - Formal skeletal structures do not include
hydrogens on any carbons (including the aldehyde C).
Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm 'H NMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants (J-values) are...
Draw the Skeletal Structure of the Unknown Compound.
Note - Formal skeletal structures do not include
hydrogens on any carbons (including the aldehyde C).
Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm 'H NMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants (J-values) are...
Spectroscopy Unknown. The spectra and data provided were
obtained from a pure organic molecule.
For 1H NMR Spectra, the integral is given in number of
hydrogens (#H) or as a relative ratio. Important coupling constants
(J-values) are listed next to the peaks for some examples. For some
spectra, an inset (grey box) is also given showing a “zoom-in” on
an important part of the spectrum.
Unknown number: 2111 Callam/Paul Chemistry 2540 Spectroscopy Unknown - 25 points Information: Each spectra below...
Draw the skeletal structure of the unknown compound
Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm 'H NMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants (J-values) are listed next to the peaks for some examples. For some spectra, an inset (grey box) is...
Draw the Skeletal Structure of the Unknown Compound.
Note - Formal skeletal structures do not include
hydrogens on any carbons (including the aldehyde C)
Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm 'H NMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants [J-values) are...
Spectroscopy Unknown
What is the Structure?
Information: Each spectra below was obtained from a pure compound. Mass Spectrum parent peaks (M) are listed for all examples. IR peaks listed are strong (s) unless otherwise indicated for signals above 1500 cm 'H NMR Spectra, the integral is given in number of hydrogens (#H) or as a relative ratio. Important coupling constants (J-values) are listed next to the peaks for some examples. For some spectra, an inset (grey box) is also given...