Kdtyjb

I am new to LaTeX and there are few things at which I am stuck.

I can draw benzene with alternate double bonds but I don't know how to draw curly arrows to show bond shifting and electrophile attack.

I would like to show reaction mechanism of benzene like this:

_{(source: chemguide.co.uk)}

_{(source: chemguide.co.uk)}

and

_{(source: ucla.edu)}

EDIT

There is one another thing I need an expert opinion. I wanted to show covalent bonding in comparison with excited and grounded state of electron. This is the code that I have written. Is there any better way to show Cl sharing its electron than what I have done (adding lots of space in my opinion is not a best way)?

And is possible to draw a curly arrow from the second box to the third to show that an electron is given energy to go to a higher energy level?

documentclass [11pt] {book}

usepackage[utf8x]{inputenc}

usepackage{ucs}

usepackage{amsmath}

usepackage{amsfonts}

usepackage{amssymb}

usepackage{chemfig}

usepackage{tikz}

begin{document}

$_4$Be~: 1s$^2$~2s$^2$

\

\

Ground State:

begin{tabular}{|c|}

hline $upharpoonleft$$downharpoonright$ \ 

hline 

end{tabular} 

begin{tabular}{|c|}

hline $upharpoonleft$$downharpoonright$ \ 

hline 

end{tabular} 

begin{tabular}{|c|c|c|}

hline ~~~&~~~&~~~\ 

hline 

end{tabular} 

\

\

Excited State:begin{tabular}{|c|}

hline $upharpoonleft$$downharpoonright$ \ 

hline 

end{tabular} 

begin{tabular}{|c|}

hline $upharpoonleft$~ \ 

hline 

end{tabular} 

begin{tabular}{|c|c|c|}

hline $upharpoonleft$~~&~~~&~~~\ 

hline 

end{tabular} 



~~~~~~~~~~~~~~~~~~~~~~~~$uparrow$~~~~~$uparrow$



~~~~~~~~~~~~~~~~~~~~~~~Cl~~~~Cl



end{document}

chemfig allows to add explizit node names to either bonds or atoms in its formulae by using the @{<name>} syntax. These names can be used in a tikzpicture with the options remember picture, overlay to draw the curved arrows. chemfig provides the wrapper chemmove for this. So a combination of chemfig and TikZ can be used to draw the schemes. (BTW: the chemfig manual actually has quite a few examples of such schemes...)

Here is something that might get you started:

documentclass{article}

usepackage{chemfig}

tikzset{

  elmove/.style={->,shorten >=3pt, shorten <=3pt}

}

begin{document}



schemestart

  chemfig{*8(-[@{sb1}]=[@{db1}]-[@{sb2}]=[@{db2}]-[@{sb3}]=[@{db3}]-[@{sb4}]=[@{db4}])}

  arrow{<->}

  chemfig{*8(=-=-=-=-)}

schemestop

chemmove[red,elmove]{

  draw (db1) .. controls  +(90:5mm) and  +(45:5mm) .. (sb1) ;

  draw (db2) .. controls +(180:5mm) and +(135:5mm) .. (sb2) ;

  draw (db3) .. controls +(270:5mm) and +(225:5mm) .. (sb3) ;

  draw (db4) .. controls   +(0:5mm) and +(315:5mm) .. (sb4) ;

  % similar the others

}



bigskip



schemestart

  chemfig{**6(----[@{b}]--)}

  arrow(benzene.base east--.base west){->[][][15pt]}

  chemfig{**[120,420,dashed]6(---(-[,-1,,,draw=none]{+})-(-[:120]H)(-[:60]NO_2)--)}

  arrow(@benzene.45--){0}[45,.2]

  chemfig{@{N}chemabove{N}{+}O_2}

schemestop

chemmove[blue,elmove]{

  draw[shorten <=-5pt] (b) .. controls +(30:5mm) and +(-90:1cm) .. (N) ;

}



end{document}

My package modiagram can be used to draw the electronic state diagram. IMHO It doesn't fit perfectly and a TikZ-only solution may be preferable. On the other hand the code is rather easy:

documentclass[11pt]{book}

usepackage[utf8]{inputenc}

usepackage{chemformula,modiagram,chemfig}



% necessary due to stupid bug in `modiagram':

newcommand*makecolonother{catcode`:=12 }



begin{document}

ch{_4Be}: 1s$^2$~2s$^2$



ground state:

begin{MOdiagram}[style=square,AO-width=8pt]

  AO(0pt){s}{0;pair}

  AO(12pt){s}{0;pair}

  AO(24pt){s}{0;}

  AO(34pt){s}{0;}

  AO(44pt){s}{0;}

  draw[overlay,red,->]

    (AO2.north) .. controls +(0,.5) and +(0,.5) .. (AO3.north) ;

end{MOdiagram}



excited state:

begin{MOdiagram}[style=square,AO-width=8pt]

  AO(0pt){s}{0;pair}

  AO(12pt){s}{0;up}

  AO(24pt){s}{0;up}

  AO(34pt){s}{0;}

  AO(44pt){s}{0;}

  makecolonother

  draw[<-,overlay]

    (AO2.south) -- ++(-100:3mm) node[below] {Cl} ;

  draw[<-,overlay]

    (AO3.south) -- ++(-80:3mm) node[below] {Cl} ;

end{MOdiagram}



end{document}