(s)-(+)-4-nitrophenylalanine methyl ester

(s)-(+)-4-nitrophenylalanine methyl ester

molar mass | 224.2 g/mol formula | C_10H_12N_2O_4 empirical formula | C_5O_2N_H_6 SMILES identifier | COC(=O)[C@H](CC1=CC=C(C=C1)[N+](=O)[O-])N InChI identifier | InChI=1/C10H12N2O4/c1-16-10(13)9(11)6-7-2-4-8(5-3-7)12(14)15/h2-5, 9H, 6, 11H2, 1H3/t9-/m0/s1 InChI key | FUFUQQWIXMPZFU-VIFPVBQESA-N

Draw the Lewis structure of (s)-(+)-4-nitrophenylalanine methyl ester. Start by drawing the overall structure of the molecule, ignoring potential double and triple bonds: Count the total valence electrons of the carbon (n_C, val = 4), hydrogen (n_H, val = 1), nitrogen (n_N, val = 5), and oxygen (n_O, val = 6) atoms: 10 n_C, val + 12 n_H, val + 2 n_N, val + 4 n_O, val = 86 Calculate the number of electrons needed to completely fill the valence shells for carbon (n_C, full = 8), hydrogen (n_H, full = 2), nitrogen (n_N, full = 8), and oxygen (n_O, full = 8): 10 n_C, full + 12 n_H, full + 2 n_N, full + 4 n_O, full = 152 Subtracting these two numbers shows that 152 - 86 = 66 bonding electrons are needed. Each bond has two electrons, so in addition to the 28 bonds already present in the diagram add 5 bonds. To minimize formal charge carbon wants 4 bonds and oxygen wants 2 bonds. Identify the atoms that want additional bonds and the number of electrons remaining on each atom: To fully fill its valence shell, nitrogen will donate one of its electrons, allowing it to form four bonds (the maximum number an element on period 2 can form). Fill in the 5 bonds by pairing electrons between adjacent highlighted atoms, noting the formal charges of the atoms. Double bonding nitrogen to the other highlighted oxygen atom would result in an equivalent molecule. The six atom ring is aromatic, so that the single and double bonds may be rearranged: Answer: | |

melting point | 222.5 °C boiling point | 468.9 °C critical temperature | 987.4 K critical pressure | 3.156 MPa critical volume | 618.5 cm^3/mol molar heat of vaporization | 80 kJ/mol molar heat of fusion | 32.7 kJ/mol molar enthalpy | -324.2 kJ/mol molar free energy | -74.71 kJ/mol (computed using the Joback method)

longest chain length | 11 atoms longest straight chain length | 5 atoms longest aliphatic chain length | 3 atoms aromatic atom count | 6 atoms H-bond acceptor count | 3 atoms H-bond donor count | 1 atom

Find the elemental composition for (s)-(+)-4-nitrophenylalanine methyl ester in terms of the atom and mass percents: atom percent = N_i/N_atoms × 100% mass percent = (N_im_i)/m × 100% Plan: • Write the chemical formula and gather atomic masses from the periodic table. • Determine values for N_i, m_i, N_atoms and m using these items. • Finally, compute the percents and check the results. Write the chemical formula: C_10H_12N_2O_4 Use the chemical formula to count the number of atoms, N_i, for each element and find the total number of atoms, N_atoms, per molecule: | number of atoms C (carbon) | 10 O (oxygen) | 4 N (nitrogen) | 2 H (hydrogen) | 12 N_atoms = 10 + 4 + 2 + 12 = 28 Divide each N_i by N_atoms to calculate atom fractions. Then use the property that atom fractions must sum to one to check the work: | number of atoms | atom fraction C (carbon) | 10 | 10/28 O (oxygen) | 4 | 4/28 N (nitrogen) | 2 | 2/28 H (hydrogen) | 12 | 12/28 Check: 10/28 + 4/28 + 2/28 + 12/28 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent C (carbon) | 10 | 10/28 × 100% = 35.7% O (oxygen) | 4 | 4/28 × 100% = 14.3% N (nitrogen) | 2 | 2/28 × 100% = 7.14% H (hydrogen) | 12 | 12/28 × 100% = 42.9% Look up the atomic mass, m_i, in unified atomic mass units, u, for each element in the periodic table: | number of atoms | atom percent | atomic mass/u C (carbon) | 10 | 35.7% | 12.011 O (oxygen) | 4 | 14.3% | 15.999 N (nitrogen) | 2 | 7.14% | 14.007 H (hydrogen) | 12 | 42.9% | 1.008 Multiply N_i by m_i to compute the mass for each element. Then sum those values to compute the molecular mass, m: | number of atoms | atom percent | atomic mass/u | mass/u C (carbon) | 10 | 35.7% | 12.011 | 10 × 12.011 = 120.110 O (oxygen) | 4 | 14.3% | 15.999 | 4 × 15.999 = 63.996 N (nitrogen) | 2 | 7.14% | 14.007 | 2 × 14.007 = 28.014 H (hydrogen) | 12 | 42.9% | 1.008 | 12 × 1.008 = 12.096 m = 120.110 u + 63.996 u + 28.014 u + 12.096 u = 224.216 u Divide the mass for each element by m to calculate mass fractions. Then use the property that mass fractions must sum to one to check the work: | number of atoms | atom percent | mass fraction C (carbon) | 10 | 35.7% | 120.110/224.216 O (oxygen) | 4 | 14.3% | 63.996/224.216 N (nitrogen) | 2 | 7.14% | 28.014/224.216 H (hydrogen) | 12 | 42.9% | 12.096/224.216 Check: 120.110/224.216 + 63.996/224.216 + 28.014/224.216 + 12.096/224.216 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent C (carbon) | 10 | 35.7% | 120.110/224.216 × 100% = 53.57% O (oxygen) | 4 | 14.3% | 63.996/224.216 × 100% = 28.54% N (nitrogen) | 2 | 7.14% | 28.014/224.216 × 100% = 12.49% H (hydrogen) | 12 | 42.9% | 12.096/224.216 × 100% = 5.395%

The first step in finding the oxidation states (or oxidation numbers) in (s)-(+)-4-nitrophenylalanine methyl ester is to draw the structure diagram. Next set every oxidation number equal to the atom's formal charge: In (s)-(+)-4-nitrophenylalanine methyl ester hydrogen is not bonded to a metal with lower electronegativity, so it will have an oxidation state of +1. Any element bonded to hydrogen gains the bonding electrons, decreasing their oxidation state by 1 for every bond: With hydrogen out of the way, look at the remaining bonds. There are 2 carbon-nitrogen bonds, 3 carbon-oxygen bonds, 2 nitrogen-oxygen bonds, and 9 carbon-carbon bonds. For each of these bonds, assign the bonding electrons to the most electronegative element. First examine the carbon-nitrogen bonds: element | electronegativity (Pauling scale) | C | 2.55 | N | 3.04 | | | Since nitrogen is more electronegative than carbon, the electrons in these bonds will go to nitrogen. Decrease the oxidation number for nitrogen in every highlighted bond (by 1 for single bonds, 2 for double bonds, and 3 for triple bonds), and increase the oxidation number for carbon accordingly: Next look at the carbon-oxygen bonds: element | electronegativity (Pauling scale) | C | 2.55 | O | 3.44 | | | Since oxygen is more electronegative than carbon, the electrons in these bonds will go to oxygen: Next look at the nitrogen-oxygen bonds: element | electronegativity (Pauling scale) | N | 3.04 | O | 3.44 | | | Since oxygen is more electronegative than nitrogen, the electrons in these bonds will go to oxygen: Next look at the carbon-carbon bonds: element | electronegativity (Pauling scale) | C | 2.55 | C | 2.55 | | | Since these elements are the same the bonding electrons are shared equally, and there is no change to the oxidation states: Now summarize the results: Answer: | | oxidation state | element | count -3 | N (nitrogen) | 1 -2 | C (carbon) | 2 | O (oxygen) | 4 -1 | C (carbon) | 4 0 | C (carbon) | 2 +1 | C (carbon) | 1 | H (hydrogen) | 12 +3 | C (carbon) | 1 | N (nitrogen) | 1

First draw the structure diagram for (s)-(+)-4-nitrophenylalanine methyl ester, and for every non-hydrogen atom, count the σ-bonds. Note that double and triple bonds consist of one σ-bond together with one or two π-bonds: Identify those atoms with lone pairs: Find the steric number by adding the lone pair count to the number of σ-bonds: Consult the following chart to determine the hybridization from the steric number: steric number | hybridization 2 | sp 3 | sp^2 4 | sp^3 5 | dsp^3 6 | d^2sp^3 7 | d^3sp^3 Assign the provisional hybridization based on the table: Next identify any sp^3 atoms with lone pair electrons which can participate in a conjugated π-bond system. These atoms can lower their energy by placing a lone pair in a unhybridized p orbital to maximize overlap with the neighboring π-bonds. Note that halogens and elements from the third period and below do not engage in bond conjugation, except in the case of aromaticity: Adjust the provisional hybridizations to arrive at the result: Answer: | |

vertex count | 28 edge count | 28 Schultz index | 6780 Wiener index | 1780 Hosoya index | 130094 Balaban index | 3.431