Nomenclature part 27

追加: 2026-05-12

[00:00:00]now in the nuclear derivatives the naming is done by keeping the name of the word benzene all right we keep the word benzene and we name it accordingly like here we can say that is phenol we can say now final remember it is a common name but there are listen carefully there are many common names there are many common names which later on was included in the iupac iupac included its common names because this name we are generally using it but what is iupac name if i ask if you ask me it is hydroxy benzene because i have what i said you i have to name this compound on the basis of benzene because benzene is a root word so hence this becomes a prefix now here it becomes perfect so what prefix means what it becomes hydroxy benzene because you know when o h becomes prefix it becomes what hydroxy benzene understood this is the actually the iupac name but this name we are not using it so much you will see that we will be studying a chapter in class 12 about it this is known as what phenol what i said phenol f e p h e n o l phenol because of that so this name we are using is a common name as well as the iups name because i said you many common names are being included in the iupac system they are included they are being considered in the ukc system we are including it all right so hence visa accordingly the naming has been done so for example suppose here it is coh is there it's a nuclear derivative you can see functional group is directly attached to the benzene ring so how do we name it this particular one now here the naming is indifferent here the names are different so here what we say here is known as benzoic acid the name means benzoic acid now you need to understand why it is benzoyl experimentation how will you come to know that where to use these where to use that all right okay fine for that reason i will be telling you one things listen carefully see when benzene ring with the benzene ring ch3 group is attached what is this known as it is known as stalwin dalwin this one is again a common name which is included in ipsc tolvin or the iupac if i say you if you ask me it is methyl benzene it is methylene correct now from tolvin listen carefully i am removing one hydrogen i am doing a hydrogen here from tolerant i am removing one hydrogen ch2 one hydrogen is removed so when i remove one hydrogen then what it becomes the naming is done in this way listen it is known as benzyl the name starts with the word benzai when talked from tolvi if you remove on hydrogen what it becomes benzyl like your sodium from methane if you remove hydrogen but it becomes methyl ethane if you remove hydrogen ethyl it becomes so from uh what you can say from here it is in benzene when ch2 group is attached and the naming starts with the word benzyl naming stats means suppose we are having cl here then what we will say benzyl chloride suppose we are having oh here the material say benzyl alcohol in this way the naming is being done okay now the next after that from benzyl if you remove another hydrogen you remove another hydrogen one more hydraulic remove it got it from benzyl then the name starts with the word the naming starts with the word benzal are you following what i'm saying the naming starts with this word benzal after that whatever is there suppose here two bonds are there now these two bond i am putting it here and i am putting oxygen here because oxygen has got a double bond then what is this it is an aldehyde cho so name will be benzaldehyde in this way the name starts with our benzolanal so that is what i am saying suppose you are having a two chlorine two bonds are there you are an iv i am attaching two chlorine here one chlorine here in one chlorine what is that it is known as benzoyl chloride receptor yes okay the name starts with the word benzal now next you see from benzar if you remove one hydrogen that means no more hydrogen is there one was there i have removed then the name starts with the word benzo as you can see it here where it is as you can see it here here with the benzene ring c is attached so what i studied the word benzo and what is this c o h is known as what oec acid so hence benzo plus oe acid what is known as benzoic acid so hence we call it as this one benzoic acid understood now how the naming is being done in this way you have to know it that benzene brings ch3 installment from tolerant if you're in one hydrogen it is benzyl from benzyl if you remove hydrogen the name starts with the word benzal from benzald if you're new on hydrogen the name starts with the word benzo as you can see one example of cumulative there is benzoic acid hence it is named in this particular way so you have to understand this all right a lot of things is there now next after that so nuclear derivatives i will come to it later on a lot of things are there in nuclear derivatives okay so next after that we are having let us say from benzene if i remove one hydrogen then what will happen what is the formula benzene first you know that it is c6h6 benzene is c6 h6 how it is c6h6 benzene c now the question is why do we represent benzene in this way why do we why don't we write c 6 x 6 because this is a molecular formula and this is a structural problem understand it the one which i am writing this is a structural formula and this formula is called as a molecular formula now how do we get it this c actually it is not possible to write in this manner all right it is not possible see c6 h6 so h6 means this is your h6 and carbon atom it is how many it is having how many bonds one two three hydrogen so one more will be a double bond then only carbon will be satisfied see this carbon is satisfied one two three and one idea four again this carbon you see one two three and one hydrogen four so alternately put single and double bond for that reason only q said that alternately single and double bond will come not it now okay so it is not possible to write whenever we will draw the structure will be writing in this way it is not possible so the easiest way to represent in this way or the keq structure which i it to you fine now what i said from this structure if i remove hydrogen let us say i am removing this idea i am removing hence i am putting this this is nothing but a bond which is weakened always remember it so in this way i have removed my hydrogen so what is the molecular formula it becomes c6 h5 cf c6 from c6h6 i have removed a hydrogen so what it becomes is 6h5 so what is the name from benzene if i removed if i remove one hydrogen is it benzyl no already we have seen it what is benzyl benzene ring ch2 is benzyl if you remove our hydrogen from benzene it is known as phenyl it is known as phenyl it's not benzine it is pheny it is said to be us remember it so hence if i put here cl then what is iupacin in chlorobenzene is said to be s because it is greatly attached to the benzene i said its a nuclear derivatives cl directly attached to the bench ending so what is cl is what chloro so it is chloro then zinc we consider that directly attached to it just now we said nuclear derivatives in that case what do you find directly if it is attached then we name it in this particular manner okay i told you like benzene ring o h what i said it becomes hydroxybenzene that one is because there o h becomes your prefix just like i said isn't it clear all these things now next after that we will come to that is we came to know this one now in benzene when the derivatives are attached to the benzene ring there are some special names given to the different positions i told you by default we consider this as the first this is second this is third this is four this is fifth this and this is six by default we consider it all right so if the derivatives is there in the first and the second carbonyl if derivatives is there derivative means suppose here one chlorine here one chlorine is attached so what we will see we will give the numbering you will say one two dichloro benzene yes you are correct iupc name is correct one two benzene what i said we need we have got some special name for it instead of saying one two what we can write we can write ortho denoted by small o ortho o r t h o o r p h ortho denoted related so we can write ortho dichloro benzene okay suppose if the same derivatives it attacks in the first and the third position one two and three it is attached first and third since two chlorines are attached they're not being said we will say one three dichlorobenzene isn't it very simple one three dichlorobenzenes instead of saying one three you know what we can say we can say mitta small m denoted by letters small m don't write mikta don't write your author write small o here it is when the derivative is then the first and third is called as meta similarly when the derivatives is there in the first and the fourth position one two three four in the first and fourth let us say cl is there then what is name one four dichlorobenzene so instead of one 4 dichloro we can say para para para para di chloro benzene this is a special name that is given to what you can say the different positions for one two we name it as ortho as i said you can see it here for one three in emitters what is that i said meta denoted by smaller for one four we name it as denoted by small p ortho meta only these three positions are there okay no other position don't say sir 1 5 what is there no 1 5 all right no name is there for 1 5 for 1 2 it is there for 1 3 is there for 1 4 it is there we don't have for 1 5 all right clear we don't have for that particular reason so hence in this way we have got ortho meta said yes now now we can also write in this way we can also say in this way because generally automata para they are basically most of the time they are being used when you go through the chapter you will come to know later on we will see the chapters at that time you see that ortho meta para is mostly used all right now next is if the derivatives is there in the first let us say right let me write the number first one two three four five six see if they are in the first and if is there first here and third and fifth you can see one one position i have left here second i have played fourth table at six seven so this is known as what's symmetrical symmetrical same throat one when i have left it so it is called symmetrical but it's symmetrical means what suppose chlorine is there so you say symmetrical trichlorobenzene symmetrical isolator letter s5m sym symmetrical trichlorobenzene or we can also write it as one three five trichlorobenzene no problem see this is the other word don't think no i can write in this word i can't write it that way no no it is the other word in the book it is there s5m it will come you'll say what is wrong it is the other word understand it other word instead of saying one three five i can say what sim symmetrical trichlorobenzene we can say that okay understood fine so this is ah the some special names are there for what you can say the benzene derivatives we consider special names are there either we can say one two or throw one three meta one four para one three five symmetrical in this way and special names are being given for it okay so you need to understand that so this is uh your what i can say is that the nuclear derivatives there are many compounds in nuclear derivatives are there you can see in your book is there many compounds in there like i as i said you that if ch3 is there it said you told me if c2h5 is there then what is this one s it is known as it benzene now we don't have a common name for it like in ch3 i told you a common name benzene ring ch3 common name was toluen but here we don't have a common name like we say it is all right clear up now next is suppose we are having here uh ch and here ch3 and ch3 all right clear so what is this known as it is called as isopropyl benzene now what is iso i told you if you remember it then if the branching is in the second carbon atom suppose there are five carbon carburetors the branching is in the second from this side if you are counting if the branching is the second or suppose you'll say no sir i will count from this side okay come from this one branching instead if the branching is in the second carbon atom there is a three square iso so here you can see one two three the branching is in the second carburetor so what is that iso and how many carbon prop three what is that propylene so what is that i said isopropyl benzene this is a ipc isopropyl benzene now here we have got a common name for it that is nothing nothing but known as cuban now common name what you need to do you have to learn it because common name is not guided by any rules common name is not guided by any rules iep is a name rules are there as i explained you that c here it is the branching is in the second carbon atom so it is iso three carbon are there prop and branching is taking place so for that reason so propyl so i've explained you but i can't say if you ask me sir why it is human because the name is given by some some or other scientists they've given it so why they gave it human god knows all right so hence you need to know it also so just remember the common you have to learn the common name that is human it is said to be as isopropyl benzene or cuban all right clear similarly if benzene ring ch double bond ch2 what is known as this is called s this is known as uh ch double bond ch2 from where we got ch double bond ch2 now listen here ch2 double bond ch2 is what you think you think none two carbon if double bond in from remember listen from the theme if i remove one hydrogen see i have removed an hydrogen from a thing then the name is called as vinyl it is known as vinyl the name is alright vinai so i can say this as vinyl benzene we can say that vinyl benzene the name is vinyl benzene clear or also we can say ephenyl benzene from ethan if you remember hydrogen that is also called as ethyne because vinyl is a common name understood so we can also say ethyl benzene there is also another name for it which is known as what styrene this is also a common name styrene all right so a lot of things you have to learn it here lot of things are there to be learnt this is called as styrene benzene ring ch double bond ch2 okay thank you