GChemPaint/C3/Aromatic-Molecular-Structures/English-timed
From Script | Spoken-Tutorial
Title of the tutorial: Aromatic-Molecular-Structures
Author: Madhuri Ganapathi
Key words: Add a six membered cycle, Add a four membered cycle, Add a bond or change the multiplicity of the existing one, Add or modify a group of atoms, Eraser, Merge two molecules, Display symbol, Benzene, fluoro(F), methyl(CH3), nitro(NO2), hydroxy(OH), carboxy, Video tutorial.
| Visual Cue | Narration
|
|---|---|
| 00:01 | Hello everyone. |
| 00:02 | Welcome to this tutorial on Aromatic Molecular Structures in GChemPaint. |
| 00:07 | In this tutorial, we will learn to |
| 00:10 | Convert Cyclohexane to Cyclohexene |
| 00:13 | Convert Cyclohexene to Benzene |
| 00:16 | Substitute Hydrogen of Benzene ring with other atoms. |
| 00:20 | Substitute Hydrogen of Benzene ring with group of atoms |
| 00:24 | Merge two molecules |
| 00:26 | Here I am using |
| 00:28 | Ubuntu Linux OS version 12.04. |
| 00:32 | GChemPaint version 0.12.10. |
| 00:37 | To follow this tutorial, you should be familiar with |
| 00:41 | GChemPaint chemical structure editor. |
| 00:44 | If not, for relevant tutorials, please visit our website. |
| 00:50 | I have opened a new GChemPaint application. |
| 00:54 | Let us first add a six membered cycle to the Display area. |
| 00:59 | Click on Add a six membered cycle tool. |
| 01:02 | Click on the Display area. |
| 01:04 | Click on Add a bond or change the multiplicity of the existing one tool. |
| 01:10 | Add two bonds on every corner of the cycle. |
| 01:14 | Position the bonds in such a way that no two bonds touch each other. |
| 01:19 | To do so, click and drag the bonds to proper positions.
|
| 01:24 | Let us display Carbon atoms on all the corners of the cycle. |
| 01:28 | Right click on any one of the corner. |
| 01:31 | A submenu appears. |
| 01:33 | Select Atom and then click on Display symbol. |
| 01:36 | Likewise, add Carbon atoms on all corners of the cycle. |
| 01:42 | To add Hydrogen atoms to the bonds, press H on the keyboard. |
| 01:47 | Click on Add or modify an atom tool. |
| 01:51 | Click on all the bond positions. |
| 01:54 | Again, see to it that no two Hydrogens overlap each other. |
| 01:59 | The obtained structure is (C6H12) Cyclohexane. |
| 02:04 | Let's copy and paste the structure. |
| 02:07 | Press CTRL+A to select the structure. |
| 02:10 | Press CTRL+C to copy and CTRL+V to paste the structure. |
| 02:15 | Let us convert the second Cyclohexane structure to Cyclohexene. |
| 02:19 | Click on the Eraser tool. |
| 02:22 | Delete one Hydrogen bond from each of the adjacent carbon atoms. |
| 02:27 | Click on Add a bond or change the multiplicity of the existing one tool. |
| 02:33 | Then click on the bond between deleted Hydrogen bonds. |
| 02:37 | A double bond is formed. |
| 02:40 | The obtained structure is Cyclohexene(C6H10) |
| 02:44 | Let us convert Cyclohexene to Cyclohexadiene and then to Benzene. |
| 02:51 | Ensure that Current element is Carbon. |
| 02:56 | Click on the Eraser tool. |
| 02:58 | Delete one Hydrogen bond from each of the adjacent Carbon atoms. |
| 03:03 | Click on Add a bond or change the multiplicity of the existing one tool. |
| 03:09 | Then click on the bond between deleted Hydrogen bonds. |
| 03:13 | A second double bond is formed. |
| 03:16 | The obtained structure is Cyclohexadiene(C6H8). |
| 03:22 | Likewise let's repeat the process to form the third double bond. |
| 03:28 | The obtained structure is Benzene(C6H6) |
| 03:33 | As an assignment. |
| 03:35 | Draw the structures of:
|
| 03:39 | *Cyclopentane and convert to Cyclopentadiene |
| 03:45 | Your completed assignment should look like this. |
| 03:49 | Next let us learn about Benzene derivatives. |
| 03:53 | Functional groups can substitute Hydrogens in Benzene, to derive various chemical compounds |
| 03:59 | Functional groups that substitute Hydrogen are |
| 04:02 | *fluoro(F), |
| 04:03 | *methyl(CH3), |
| 04:04 | *nitro(NO2), |
| 04:05 | *hydroxy(OH) and |
| 04:06 | * others. |
| 04:08 | Let us copy and paste the Benzene structure twice, on the Display area. |
| 04:13 | Click on Select one or more objects tool to select the Benzene structure. |
| 04:18 | Press CTRL+C to copy and press CTRL+V twice to paste the structures. |
| 04:24 | Let's Substitute Hydrogen of the first Benzene structure with a Fluorine atom. |
| 04:30 | Press F on the keyboard. |
| 04:32 | Click on Add or modify an atom tool. |
| 04:35 | Click on Hydrogen to substitute it with Fluorine. |
| 04:40 | The obtained structure is Fluorobenzene. |
| 04:44 | Next let's substitute the Hydrogen of the second Benzene with a group of atoms. |
| 04:50 | Click on Add or modify a group of atoms tool. |
| 04:54 | Click on any one of the Hydrogens. |
| 04:04 | Observe that Hydrogen is enclosed in a green box with a blinking cursor. |
| 05:03 | Let's substitute Hydrogen with a methy group. |
| 05:06 | Remove Hydrogen and type capital C H and 3 |
| 05:12 | Click anywhere on the Display area. |
| 05:15 | The obtained structure is Methyl benzene. |
| 05:19 | Let's substitute Hydrogen of the third Benzene with a nitro group. |
| 05:24 | Click on any one of the Hydrogens. |
| 05:27 | Remove Hydrogen and type capital N O 2 |
| 05:32 | The obtained structure is Nitrobenzene. |
| 05:36 | Let's see Carbon positions in the Benzene ring. |
| 05:40 | Six Carbon atoms are numbered from 1 to 6 in Benzene. |
| 05:45 | All six positions are equivalent, before Hydrogen is substituted. |
| 05:51 | Electron density of the ring changes, when Hydrogen is substituted by a functional group. |
| 05:57 | Electron density is dependent on the Substituent. |
| 06:01 | A mono-substituted compound of Benzene can be substituted at positions: |
| 06:06 | * 1 and 4- as Para. |
| 06:09 | * 2 and 6- as Ortho. |
| 06:12 | * 3 and 5- as Meta. |
| 06:15 | Now let's substitute Methylbenzene structure with another methyl group. |
| 06:20 | Click on Add or modify a group of atoms tool. |
| 06:24 | Click on the second Hydrogen position of the ring. |
| 06:28 | To substitute Hydrogen in the green box with methyl group, |
| 06:32 | type capital C H 3. |
| 06:35 | The new structure obtained is ortho-Xylene.
|
| 06:39 | Let's substitute Nitrobenzene with a Carboxy group. |
| 06:44 | Click on the fourth Hydrogen position of the ring. |
| 06:48 | To substitute Hydrogen in the green box with Carboxy group, |
| 06:52 | type capital C O O H |
| 06:57 | The new structure obtained is para-Nitrobenzoic acid. |
| 07:02 | Press CTRL+Z to undo the process. |
| 07:05 | Substitute third Hydrogen position of Nitrobenzene with a nitro group. |
| 07:11 | Remove Hydrogen and type capital N O 2 |
| 07:17 | The new structure obtained is meta-Dinitrobenzene. |
| 07:22 | Here is an assignment. |
| 07:24 | Draw seven Benzene structures. |
| 07:25 | Substitute one of the Hydrogens of: |
| 07:28 | First Benzene with bromo. |
| 07:30 | Second Benzene with iodo. |
| 07:32 | Third Benzene with hydroxy. |
| 07:34 | Fourth Benzene with amino. |
| 07:36 | Fifth Benzene with ethyl. |
| 07:39 | Also substitute:
Two of the Hydrogens of the sixth Benzene with Chlorine atoms. |
| 07:44 | First and fourth Hydrogen positions of the seventh Benzene with Carboxy groups. |
| 07:51 | Your completed assignment should look like this. |
| 07:55 | Now, let's learn to merge two structures. |
| 07:57 | Let's open a new window. |
| 08:00 | Ensure that current element is Carbon. |
| 08:04 | Click on the Add a four membered cycle tool. |
| 08:07 | Click on the Display area twice. |
| 08:10 | Click on Select one or more objects tool. |
| 08:14 | Click on the second structure. |
| 08:16 | Drag it and place it close to the first structure |
| 08:20 | such that they touch each other. |
| 08:23 | Press CTRL+A to select the structures. |
| 08:26 | Merge two molecules tool becomes active. |
| 08:30 | Click on Merge two molecules tool, to merge the molecules. |
| 08:34 | Drag the structures to observe merging. |
| 08:38 | Let's summarize what we have learnt. |
| 08:41 | In this tutorial, we have learnt to |
| 08:43 | Convert Cyclohexane to Cyclohexene |
| 08:46 | Convert Cyclohexene to Benzene |
| 08:49 | Substitute Hydrogen of Benzene with fluoro, methyl, nitro and carboxy groups. |
| 08:55 | Merge two four membered cycles. |
| 08:58 | Here is an assignment. |
| 09:00 | Merge
Two Benzene molecules |
| 09:02 | Two Pentane structures |
| 09:04 | Cyclopentane and Cyclohexane molecules. |
| 09:08 | Your completed assignment should look like this. |
| 09:12 | Watch the video available at this link. |
| 09:15 | It summarizes the Spoken Tutorial project |
| 09:19 | If you do not have good bandwidth, you can download and watch it |
| 09:23 | The Spoken Tutorial Project Team:
Conducts workshops using spoken tutorials |
| 09:27 | Gives certificates to those who pass an on-line test |
| 09:31 | For more details, please write to
contact@spoken-tutorial.org |
| 09:37 | Spoken Tutorial Project is a part of the Talk to a Teacher project . |
| 09:41 | It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
| 09:48 | More information on this Mission is available at this link . |
| 09:53 | This is Madhuri Ganapathi from IIT Bombay signing off. |
| 09:57 | Thank you for joining. |
