ATOM O1 ATOM N2 ATOM O2 ATOM N1 ATOM N2 ATOM C

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Blaise Lee
5 years ago
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1 I. (8 points) ame Page 1 AMPA, shown below, is a synthetic compound that mimics the effects of the neurotransmitter glutamate. When evaluating the structure of this compound, please remember to take into account all other major and valid resonance contributors (as always). ATM C ATM (a) For each of the atoms indicated with an arrow, provide the atom's most reasonable hybridization as well as its electronic geometry (VEPR), and observable geometry (shape). C ATM ATM 1 ATM ybridization Electronic geometry bservable geometry ATM 1 AMPA ATM 1 ATM 1 ATM ATM C (b) Circle the most basic atom in AMPA (c) ne of the reactive bonding motifs that is found within AMPA is shown below as Contributor 1. Its reactivity and structure can be best explained with a set of resonance contributors. Draw all other resonance contributors for this structure that contain all closed shell atoms and atomic formal charges between +1 and -1. C Contributor 1 6 (d) Assuming the hybridization model for all atoms and considering all resonance contributors above, provide an accurate and complete three-dimensional orbital picture for Contributor 1. As always, you should use lines, dashes, wedges, p orbitals (lone or overlapping) to show the direction of all electrons (or empty orbitals) in your drawing. All bond angles should reflect the appropriate geometry and hybridization chosen for your drawing. 10

2 II. (1 points) A. (a) DU is a large, bulky base; its most basic site is easily predicted by considering its other major all-closed shell resonance contributor. DU pka of conjugate acid ~1 ame Page other all closed shell resonance contributor (b) DU will react as a base in each of the following situations. Draw the product(s) most likely to form. If a proton transfer is predicted to occur, estimate the, (whether or not the reaction has a Keq >1). If the reaction is not a proton transfer, simply write A in the exponent box. Reaction 1 Product(s) C Reaction Product(s) C a C Reaction 1 Reaction provide the exponent or write A C Reaction provide the exponent or write A Reaction Product(s). DDT provide the exponent or write A Despite falling out of favor decades ago, the insecticide DDT is once again being considered for use in areas suffering from malaria outbreaks (even in Michigan). Rank the indicated bonds (a-f) in order of predicted length, from longest to shortest. If any are predicted to be the same length, put a circle around them. a b f c d e Longest hortest

3 A. III. (16 points) ame Page Glyphosate is a potent herbicide sold by Monsanto under the name of RoundUp (TM). Its use ignited the development of a generation of genetically modified, "RoundUp Ready," crops that can be grown even with the use of this potent herbicide. It is shown below in its fully protonated form; the pkas for each of its acidic protons are given. Glyphosophate (RoundUp) pka. C pka 11 P pka pka 6 (a) RoundUp is most effective at a p ~6. Draw the predominant structure(s) of glyphosphate found at p 6. (b) The RoundUp is far less effective when the p of the soil is above 11 (often caused by fertilizers). Draw the predominant structure(s) found at p 1.. Analyze each of the following organic structures (all non-bonding electrons are shown) very carefully. Then determine whether each structure is valid or contains any flaw(s). e sure to explain your answer completely. This structure is (circle one): Valid Flawed This structure is (circle one): Valid Flawed C P i

4 IV. (1 points) ame Page A. The drawing labeled "1" below (molecular formula C 6 ) contains an imidazole ring. Imidazole is an organic compound that plays a very important role in biological systems. For each of the other drawings, circle the description that best matches the relationship between the drawing given and drawing 1. is : is : 1 is : is :. Working with the same molecular formula as in the problem above (C 6 ) draw valid and complete Lewis structures with the following criteria: This compound contains: 1) all closed shell atoms ) a ring containing 6 atoms ) no hydrogen bond donor sites ) no atoms carry formal charge This compound contains: 1) all closed shell atoms ) a ring containing only carbon atoms ) two sp hybridized atoms ) no atoms carry formal charge

5 V. (1 points) A. ame Page Fill in the missing curved arrow mechanisms for each step of the following biologically relevant transformation (- is a general proton donor, and its conjugate base may act as a proton acceptor): (a) (b). ac (an ionic compound) reacts with Al in a complexation reaction. Draw complete Lewis structures for all reactants and products of this reaction (make sure your reaction is balanced). Remember that Al acts like its column-mate, boron. (a) (b) (c) C. Assuming the hybridization model for all atoms and considering resonance when applicable, provide an accurate and complete three-dimensional orbital picture for Al. As always, you should use lines, dashes, wedges, p orbitals (lone or overlapping) to show the direction of all electrons (or empty orbitals) in your drawing. All bond angles should reflect the appropriate geometry and hybridization chosen for your drawing. Each of the following compounds shown below can be drawn as a set of resonance contributors; a less important one of the set is given. Draw the MT important, all closed shell resonance contributor for each compound. F

1.5 h; 100 points Signature UM ID # Problem Points Score GSI I 17 II 20 III 20 IV 19 V 24 Total

1.5 h; 100 points Signature UM ID # Problem Points Score GSI I 17 II 20 III 20 IV 19 V 24 Total hemistry 10 First ame First Examination Last ame May 0, 01 please print clearly 1.5 h; 100 points ignature UM ID # PRIT TE FIRT LETTER F YUR LAT AME ERE: Problem Points core GI I 17 II 0 III 0 IV 19 V