Input interpretation
dimethylphenylmagnesium chloride
Basic properties
molar mass | 164.9 g/mol formula | C_8H_9ClMg empirical formula | C_8Mg_Cl_H_9 InChI identifier | InChI=1/C8H9.ClH.Mg/c1-7-5-3-4-6-8(7)2;;/h3-5H, 1-2H3;1H;/q;;+1/p-1/fC8H9.Cl.Mg/h;1h;/q;-1;m InChI key | SADDAWAHJLQMRW-UHFFFAOYSA-M
Lewis structure
Draw the Lewis structure of dimethylphenylmagnesium chloride. 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), chlorine (n_Cl, val = 7), hydrogen (n_H, val = 1), and magnesium (n_Mg, val = 2) atoms: 8 n_C, val + n_Cl, val + 9 n_H, val + n_Mg, val = 50 Calculate the number of electrons needed to completely fill the valence shells for carbon (n_C, full = 8), chlorine (n_Cl, full = 8), hydrogen (n_H, full = 2), and magnesium (n_Mg, full = 4): 8 n_C, full + n_Cl, full + 9 n_H, full + n_Mg, full = 94 Subtracting these two numbers shows that 94 - 50 = 44 bonding electrons are needed. Each bond has two electrons, so in addition to the 19 bonds already present in the diagram add 3 bonds. To minimize formal charge carbon wants 4 bonds. Identify the atoms that want additional bonds and the number of electrons remaining on each atom: Fill in the 3 bonds by pairing electrons between adjacent highlighted atoms. Note that the six atom ring is aromatic, so that the single and double bonds may be rearranged: Answer: | |
Quantitative molecular descriptors
longest chain length | 6 atoms longest straight chain length | 2 atoms longest aliphatic chain length | 0 atoms aromatic atom count | 6 atoms H-bond acceptor count | 0 atoms H-bond donor count | 0 atoms
Elemental composition
Find the elemental composition for dimethylphenylmagnesium chloride 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_8H_9ClMg Use the chemical formula, C_8H_9ClMg, to count the number of atoms, N_i, for each element and find the total number of atoms, N_atoms: | number of atoms C (carbon) | 8 Mg (magnesium) | 1 Cl (chlorine) | 1 H (hydrogen) | 9 N_atoms = 8 + 1 + 1 + 9 = 19 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) | 8 | 8/19 Mg (magnesium) | 1 | 1/19 Cl (chlorine) | 1 | 1/19 H (hydrogen) | 9 | 9/19 Check: 8/19 + 1/19 + 1/19 + 9/19 = 1 Compute atom percents using the atom fractions: | number of atoms | atom percent C (carbon) | 8 | 8/19 × 100% = 42.1% Mg (magnesium) | 1 | 1/19 × 100% = 5.26% Cl (chlorine) | 1 | 1/19 × 100% = 5.26% H (hydrogen) | 9 | 9/19 × 100% = 47.4% 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) | 8 | 42.1% | 12.011 Mg (magnesium) | 1 | 5.26% | 24.305 Cl (chlorine) | 1 | 5.26% | 35.45 H (hydrogen) | 9 | 47.4% | 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) | 8 | 42.1% | 12.011 | 8 × 12.011 = 96.088 Mg (magnesium) | 1 | 5.26% | 24.305 | 1 × 24.305 = 24.305 Cl (chlorine) | 1 | 5.26% | 35.45 | 1 × 35.45 = 35.45 H (hydrogen) | 9 | 47.4% | 1.008 | 9 × 1.008 = 9.072 m = 96.088 u + 24.305 u + 35.45 u + 9.072 u = 164.915 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) | 8 | 42.1% | 96.088/164.915 Mg (magnesium) | 1 | 5.26% | 24.305/164.915 Cl (chlorine) | 1 | 5.26% | 35.45/164.915 H (hydrogen) | 9 | 47.4% | 9.072/164.915 Check: 96.088/164.915 + 24.305/164.915 + 35.45/164.915 + 9.072/164.915 = 1 Compute mass percents using the mass fractions: Answer: | | | number of atoms | atom percent | mass percent C (carbon) | 8 | 42.1% | 96.088/164.915 × 100% = 58.27% Mg (magnesium) | 1 | 5.26% | 24.305/164.915 × 100% = 14.74% Cl (chlorine) | 1 | 5.26% | 35.45/164.915 × 100% = 21.50% H (hydrogen) | 9 | 47.4% | 9.072/164.915 × 100% = 5.501%
Elemental oxidation states
The first step in finding the oxidation states (or oxidation numbers) in dimethylphenylmagnesium chloride is to draw the structure diagram. Next set every oxidation number equal to the atom's formal charge: In dimethylphenylmagnesium chloride 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 1 carbon-magnesium bond, 1 carbonl-magnesium bond, and 8 carbon-carbon bonds. For each of these bonds, assign the bonding electrons to the most electronegative element. First examine the carbon-magnesium bond: element | electronegativity (Pauling scale) | C | 2.55 | Mg | 1.31 | | | Since carbon is more electronegative than magnesium, the electrons in this bond will go to carbon. Decrease the oxidation number for carbon (by 1 for single bonds, 2 for double bonds, and 3 for triple bonds), and increase the oxidation number for magnesium accordingly: Next look at the carbonl-magnesium bond: element | electronegativity (Pauling scale) | Cl | 3.16 | Mg | 1.31 | | | Since chlorine is more electronegative than magnesium, the electrons in this bond will go to chlorine: 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 | C (carbon) | 2 -1 | C (carbon) | 4 | Cl (chlorine) | 1 0 | C (carbon) | 2 +1 | H (hydrogen) | 9 +2 | Mg (magnesium) | 1
Orbital hybridization
First draw the structure diagram for dimethylphenylmagnesium chloride, 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: | |
Topological indices
vertex count | 19 edge count | 19 Schultz index | 2237 Wiener index | 586 Hosoya index | 2906 Balaban index | 3.293