trimethylsilyl amide

trimethylsilyl amide

molar mass | 88.2 g/mol formula | (C_3H_10NSi)^- empirical formula | C_3Si_N_H_10 SMILES identifier | C[Si](C)(C)[NH-] InChI identifier | InChI=1/C3H10NSi/c1-5(2, 3)4/h4H, 1-3H3/q-1 InChI key | USXXUTHCANUHBW-UHFFFAOYSA-N

Draw the Lewis structure of trimethylsilyl amide. Start by drawing the overall structure of the molecule: Count the total valence electrons of the carbon (n_C, val = 4), hydrogen (n_H, val = 1), nitrogen (n_N, val = 5), and silicon (n_Si, val = 4) atoms, including the net charge: 3 n_C, val + 10 n_H, val + n_N, val + n_Si, val - n_charge = 32 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 silicon (n_Si, full = 8): 3 n_C, full + 10 n_H, full + n_N, full + n_Si, full = 60 Subtracting these two numbers shows that 60 - 32 = 28 bonding electrons are needed. Each bond has two electrons, so the above diagram has all the necessary bonds. There are 14 bonds and hence 28 bonding electrons in the diagram. Fill in the remaining unbonded electrons on each atom. In total, there remain 32 - 28 = 4 electrons left to draw. Lastly, fill in the formal charges: Answer: | |

longest chain length | 3 atoms longest straight chain length | 3 atoms longest aliphatic chain length | 0 atoms aromatic atom count | 0 atoms H-bond acceptor count | 1 atom H-bond donor count | 0 atoms

Find the elemental composition for trimethylsilyl amide 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_3H_10NSi)^- 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) | 3 Si (silicon) | 1 N (nitrogen) | 1 H (hydrogen) | 10 N_atoms = 3 + 1 + 1 + 10 = 15 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) | 3 | 3/15 Si (silicon) | 1 | 1/15 N (nitrogen) | 1 | 1/15 H (hydrogen) | 10 | 10/15 Check: 3/15 + 1/15 + 1/15 + 10/15 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent C (carbon) | 3 | 3/15 × 100% = 20.0% Si (silicon) | 1 | 1/15 × 100% = 6.67% N (nitrogen) | 1 | 1/15 × 100% = 6.67% H (hydrogen) | 10 | 10/15 × 100% = 66.7% 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) | 3 | 20.0% | 12.011 Si (silicon) | 1 | 6.67% | 28.085 N (nitrogen) | 1 | 6.67% | 14.007 H (hydrogen) | 10 | 66.7% | 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) | 3 | 20.0% | 12.011 | 3 × 12.011 = 36.033 Si (silicon) | 1 | 6.67% | 28.085 | 1 × 28.085 = 28.085 N (nitrogen) | 1 | 6.67% | 14.007 | 1 × 14.007 = 14.007 H (hydrogen) | 10 | 66.7% | 1.008 | 10 × 1.008 = 10.080 m = 36.033 u + 28.085 u + 14.007 u + 10.080 u = 88.205 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) | 3 | 20.0% | 36.033/88.205 Si (silicon) | 1 | 6.67% | 28.085/88.205 N (nitrogen) | 1 | 6.67% | 14.007/88.205 H (hydrogen) | 10 | 66.7% | 10.080/88.205 Check: 36.033/88.205 + 28.085/88.205 + 14.007/88.205 + 10.080/88.205 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent C (carbon) | 3 | 20.0% | 36.033/88.205 × 100% = 40.85% Si (silicon) | 1 | 6.67% | 28.085/88.205 × 100% = 31.84% N (nitrogen) | 1 | 6.67% | 14.007/88.205 × 100% = 15.88% H (hydrogen) | 10 | 66.7% | 10.080/88.205 × 100% = 11.43%

The first step in finding the oxidation states (or oxidation numbers) in trimethylsilyl amide is to draw the structure diagram. Next set every oxidation number equal to the atom's formal charge: In trimethylsilyl amide 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 3 carbon-silicon bonds, and 1 nitrogen-silicon bond. For each of these bonds, assign the bonding electrons to the most electronegative element. First examine the carbon-silicon bonds: element | electronegativity (Pauling scale) | C | 2.55 | Si | 1.90 | | | Since carbon is more electronegative than silicon, the electrons in these bonds will go to carbon. Decrease the oxidation number for carbon in every highlighted bond (by 1 for single bonds, 2 for double bonds, and 3 for triple bonds), and increase the oxidation number for silicon accordingly: Next look at the nitrogen-silicon bond: element | electronegativity (Pauling scale) | N | 3.04 | Si | 1.90 | | | Since nitrogen is more electronegative than silicon, the electrons in this bond will go to nitrogen: Now summarize the results: Answer: | | oxidation state | element | count -4 | C (carbon) | 3 -3 | N (nitrogen) | 1 +1 | H (hydrogen) | 10 +4 | Si (silicon) | 1

First draw the structure diagram for trimethylsilyl amide, 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 Now assign the hybridization for each atom: Answer: | |

vertex count | 15 edge count | 14 Schultz index | 1060 Wiener index | 298 Hosoya index | 288 Balaban index | 5.776