Question

For all spectral analysis, show your complete analysis and provide evidence for your proposed structure. Basic Spectroscopy i. Determine the index of hydrogen deficiency for the following a) C3H7NO b) C4H4BrNO2 c) C21H22N202 ii. Calculate the molecular formulas for possible compounds with molecular masses of 136, using the Rule of Thirteen. You may assume that the only other atoms present in each molecule are carbons and hydrogens. a) A compound with two oxygen atoms b) A compound with two nitrogen atoms and one oxygen atom c) A compound with five carbon atoms and our oxygen atoms

Answer 1

SORO Nitrogen rule of Rule of thirteen when the ndecular weight of compound is. odd indicates, odd number of nitrogens present in molecule. - and when molecular weight of compound is odd number Indicates even number of nitrogen. present or No nitrogen. sites of unsaturation a) If Each oxygen) and sulphur present then they 1. are neglected] b) If Nitrogen aton is present Replace it bytch c) If halogens are present E, cl, Br, I Replace it by I only hydrogen] DC8Hy NO Doxygen neglected. 2) Nitrogen = add_dhe therefore m.f=ca Hot molecular weight = 133 (C&HANO) The molecular formula has 8 Hydrogen after applying Nitrogen addition. In Hanta = cg Haxg+2= Cg H2o - Cg H2o-Cg Hg = 12 hydrogen deficient. Hence 12 2 = 5 sites of unsaturation The odd mass number of nitrogen present. Indicates odd no.

2) CAH BY NOR mass = 177 Halogen add H . Nitrogen add -&H oxygen neglect. Hence molecular formula is . CH BONO2 mass = lgl (csH BY NOR) odd mass number Indicates odd number of Nitrogen site of unsaturation an Hantz - SHaxstza Hiz Cs His coho = 6 hydrogen deficient. Hence 6 = 3 sites of unsaturation 3) C2 H₂2N2O2 mas 334 even = oxygen = neglect it. Nitrogen = add - CH Hence. Molecular formula is C23 Hay N202 mass =360 even mass number indicates even number of nitrogen present.' the

* molecular weight 136 Hence for » compound with two oxygen atom. Hence molecular formula is (сано, (2+8) + (1+8) + (16+2) = 136 site of unsaturation. In Hantz co tx 8+2 = ( 8 H, 8.-C848. Ho s site of unsaturation

compound ох<a en with two nitrogen and one molecular formula is cq HONZO If Nitrogen add - CH Hence Cg H. No. site of unsaturation. Can Manta) Cg Haxgte - Cg H2O Cg H2o - Catho = 10 = 15 five site of unsaturation 3) compound with 5 carbon one oxygen. molecular formula must be. Cgtzo site of unsaturation cg Haagt2 = Cg H20 Catzo - Cattaa 8 - 4 To satisfy molecular weight four site of unsaturation.