chemfig
Gallery
Gallery
This manual concludes with drawings of molecules of varying complexity.
The curious user can look at the ⟨code⟩ of each molecule, though it does become less attractive the more complex the molecule gets. Indeed, beyond a certain level of complexity, though it it is fairly easy to write ⟨code⟩, it becomes much harder to read the ⟨code⟩ to analyze it afterwards. We quickly reached the limits of immediate readability of the code of a complex drawing.
Anyway, I hope that this package will help all LaTeX users wishing to draw molecules. Although chemfig has been thoroughly tested and although its version number is now greater than 1.0, I hope that you will be forgiving with bugs you encounter and send me an email to let me know of any malfunctions or suggestions for improvement.
Christian Tellechea
0pt \(\star\) \(\star\quad\star\)
2-methylpentane
\chemfig{[7]H_3C-CH(-[6]CH_3)-[1]CH_2-CH_2-[1]CH_3}
3-ethyl-2-methylhexane
\chemfig{H_3C-[7]CH(-[6]CH_3)-[1]CH(-[7]C_3H_7)-[2]CH_2-[3]H_3C}
Stearine, condensed structural diagram
\definesubmol{@}{([0,2]-O-[0,1]C(=[2,1]O)-C_{17}H_{33})}
\chemfig{[2,2]CH_2!@-CH_{\phantom 2}!@-CH_2!@}
Stearine, skeleton diagram
\definesubmol{x}{-[:+30,.6]-[:-30,.6]}
\definesubmol{y}{-O-(=[2,.6]O)-!x!x!x!x!x!x!x!x}
\chemfig{[2]([0]!y)-[,1.5]([0]!y)-[,1.5]([0]!y)}
Methyl 2-methylpropanoate
\chemfig{H_3C-CH_2(-[2]CH_3)-C(=[1]O)-[7]O-CH_3}
Vanillin
\chemfig{HC*6(-C(-OH)=C(-O-[::-60]CH_3)-CH=C(-[,,,2]HC=[::-60]O)-HC=[,,2])} \quad or \quad
\chemfig{*6(-(-OH)=(-OCH_3)-=(-=[::-60]O)-=)}
Caffeine
\chemfig{*6((=O)-N(-CH_3)-*5(-N=-N(-CH_3)-=)--(=O)-N(-H_3C)-)}
Aspirin
\chemfig{*6(-=-(-O-[::-60](=[::-60]O)-[::+60])=(-(=[::+60])-[::-60]OH)-=)}
Aspirin is a registered trademark of Bayer in many countries.
Phthalic anhydride
\chemfig{*6(=*5(-(=O)-O-(=O)-)-=-=-)}
Camphor
\chemfig{*6(-(<:[::120](-[::-100,0.7])(-[::100,0.7]))--(=O)-(-)(<:[::120])--)}
\quad or \quad
\setchemfig{cram width=3pt}
\chemfig{<[:10](>[:85,1.8]?(-[:160,0.6])-[:20,0.6])
>[:-10]-[:60](=[:30,0.6]O)-[:170]?(-[:30,0.6])-[:190]-[:240]}
Triphenylmethane
\chemfig{*6(-=-*6(-(-*6(=-=-=-))-*6(=-=-=-))=-=)}
\quad or \quad
\definesubmol{@}{*6(=-=-=-)}
\chemfig{(-[:-30]!@)(-[:90]!@)(-[:210]!@)}
Amygdalin
\setchemfig{cram width=2pt}
\definesubmol{c1}{-[:200]-[:120]O-[:190]}
\definesubmol{c2}{-[:170](-[:200,0.7]HO)<[:300](-[:170,0.6]HO)
-[:10,,,,line width=2pt](-[:-40,0.6]OH)>[:-10]}
\definesubmol{csub}{-[:155,0.65]-[:90,0.65]}
\chemfig{O(!{c1}(!{csub}O(!{c1}(!{csub}OH)!{c2}))!{c2})-[:-30](-[:-90]CN)-[:30]*6(=-=-=-)}
Adenosine triphosphate
\setchemfig{cram width=3pt}
\definesubmol{a}{-P(=[::-90,0.75]O)(-[::90,0.75]HO)-}
\chemfig{[:-54]*5((--[::60]O([::-60]!aO([::-60]!aO([::60]!aHO))))<(-OH)
-[,,,,line width=2pt](-OH)>(-N*5(-=N-*6(-(-NH_2)=N-=N-)=_-))-O-)}
Viagra
\chemfig{N*6((-H_3C)---N(-S(=[::+120]O)(=[::+0]O)-[::-60]*6(-=-(-O-[::-60]-[::+60]CH_3)
=(-*6(=N-*5(-(--[::-60]-[::+60]CH_3)=N-N(-CH_3)-=)--(=O)-N(-H)-))-=))---)}
Cholesterol ester
\chemfig{[:30]R-(=[::+60]O)-[::-60]O-*6(--*6(=--*6(-*5(---(-(-[::+60]Me)
-[::-60]-[::-60]-[::+60]-[::-60](-[::-60]Me)-[::+60]Me)-)-(-[::+0]Me)---)--)-(-[::+0]Me)---)}
Porphyrin
\chemfig{?=[::+72]*5(-N=(-=[::-72]*5(-[,,,2]HN-[,,2](=-[::-36]*5(=N-(=-[::-72]*5(-NH-[,,1]?=-=))
-=-))-=-))-=-)}
Manganese 5,10,15,20-tetra(N-ethyl-3-carbazolyl) porphyrin
\definesubmol{A}{*6(=-*5(-*6(-=-=-)--N(--[::-60])-)=-=-)}
\chemfig{([::+180]-!A)=[::+72]*5(-N=(-(-[::+54]!A)=[::-72]*5(-N(-[::-33,1.5,,,draw=none]Mn)
-(=(-[::+72]!A)-[::-36]*5(=N-(=(-[::+54]!A)-[::-72]*5(-N-(-)=-=))-=-))-=-))-=-)}
Penicillin
\chemfig{[:-90]HN(-[::-45](-[::-45]R)=[::+45]O)>[::+45]*4(-(=O)-N*5(-(<:(=[::-60]O)
-[::+60]OH)-(<[::+0])(<:[::-108])-S>)--)}
LSD
\chemfig{[:150]?*6(=*6(--*6(-N(-CH_3)--(<(=[::+60]O)-[::-60]N(-[::+60]-[::-60])
-[::-60]-[::+60])-=)([::-120]<H)---)-*6(-=-=-(-[::-30,1.155]\chembelow{N}{H}?)=))}
Strychnine
\chemfig{*6(=-*6(-N*6(-(=O)--([::-120]<:H)*7(-O--=?[0]([::-25.714]-[,2]?[1]))
-*6(-?[0,{>}]--(<N?[1]?[2])-(<[::-90]-[::-60]?[2]))(<:[::+0]H)-([::+120]<H))--?)=?-=-)}
Codeine
\chemfig{[:-30]**6(-(-OH)-?-*6(-(-[3]-[2,2]-[0,.5])*6(-(<:[:-150,1.155]O?)
-(<:OH)-=-)-(<:[1]H)-(-[2]NCH_3)--)---)}
A dye (red)
\chemfig{**6(--*6(-(-NO_2)=-(-\charge{90=\|,-90=\|}{O}-[0]H)=(-\charge{180=\|}{N}=[0]\charge{90=\|}{N}-[0]Ar)-)----)}
Menthone
\chemfig{CH_3-?(-[2]H)(-[::-30,2]-[::+60](=[1]\charge{0=\|,90=\|}{O})
-[::-150,1.5](-[:20]CH(-[1]CH_3)(-[7]CH_3))(-[6]H)-[::-90,2]-[::+60]?)}
Fullerene
\definesubmol\fragment1{
(-[:#1,0.85,,,draw=none]
-[::126]-[::-54](=_#(2pt,2pt)[::180])
-[::-70](-[::-56.2,1.07]=^#(2pt,2pt)[::180,1.07])
-[::110,0.6](-[::-148,0.60](=^[::180,0.35])-[::-18,1.1])
-[::50,1.1](-[::18,0.60]=_[::180,0.35])
-[::50,0.6]
-[::110])
}
\chemfig{
!\fragment{18}
!\fragment{90}
!\fragment{162}
!\fragment{234}
!\fragment{306}
}
Fischer indole synthesis
\schemestart
\chemfig{*6(=-*6(-\chembelow{N}{H}-NH_2)=-=-)}
\+
\chemfig{(=[:-150]O)(-[:-30]R_2)-[2]-[:150]R_1}
\arrow(.mid east--.mid west){->[\chemfig{H^+}]}
\chemfig{*6(-=*5(-\chembelow{N}{H}-(-R_2)=(-R_1)-)-=-=)}
\schemestop
Reaction mechanisms: carbonyl group
\schemestart
\chemfig{C([3]-)([5]-)=[@{db,.5}]@{atoo}\charge{0=\|,-90=\|}{O}}
\arrow(.mid east--.mid west){<->}
\chemfig{\charge{90:3pt=$\scriptstyle\oplus$}{C}([3]-)([5]-)-%
\charge{0=\|,90=\|,-90=\|,45:3pt=$\scriptstyle\ominus$}{O}}
\schemestop
\chemmove{\draw[shorten <=2pt, shorten >=2pt](db) ..controls +(up:5mm) and +(up:5mm)..(atoo);}
Reaction mechanisms: nitro group
\schemestart
\chemfig{R-\charge{225:3pt=$\scriptstyle\oplus$}{N}([1]=[@{db}]@{atoo1}O)([7]-[@{sb}]@{atoo2}
\charge{45=\|,-45=\|,-135=\|,45:5pt=$\scriptstyle\ominus$}{O})}
\arrow(.mid east--.mid west){<->}
\chemfig{R-\charge{135:3pt=$\scriptstyle\oplus$}{N}([1]-\charge{90:3pt=$\scriptstyle\ominus$}{O})([7]=O)}
\schemestop
\chemmove{
\draw[shorten <=2pt, shorten >=2pt](db) ..controls +(120:5mm) and +(120:7mm)..(atoo1);
\draw[shorten <=3pt, shorten >=2pt](atoo2) ..controls +(225:10mm) and +(225:10mm)..(sb);
}
Calcium alginate gel
\definesubmol{0}{-[-3,.15,,,draw=none]}% invisible bond to stack
\definesubmol{COO/Na+}1{-[7]((-[-3,.66]COO^{-}!0N|a^+#1))}
\definesubmol{chain}{-[5]!{COO/Na+}{}-[5]!{COO/Na+}{}-[5]-[7]}
\definesubmol{COO/Ca2+}1{-[7]((-[-3,.66]COO^{-}!0C|a^{2+}!0COO^{-}-[-3,.66](-[7]-[5])#1))}
\hreac[fixed length,atom sep=2.5em,angle increment=30]
\chemfig{-[5]!{COO/Na+}{!0\phantom{C}!0(!{COO/Na+}{}!{chain})(-[-1])}!{chain}}
>[\printatom{Ca^{2+}}]
\chemfig{-[5]!{COO/Ca2+}{(-[-1]-[1])}-[5]!{COO/Ca2+}{}-[5]!{COO/Ca2+}{}-[5]-[7]}
\endhreac
Nucleophilic addition. Primary amines
\setchemfig{atom sep=2.5em,compound sep=5em}
\schemestart
\chemfig{R-@{aton}\charge{90=\|}{N}H_2}
\+
\chemfig{@{atoc}C([3]-CH_3)([5]-CH_3)=[@{atoo1}]O}
\chemfig{@{atoo2}\chemabove{H}{\scriptstyle\oplus}}
\chemmove[-stealth,shorten <=3pt,dash pattern= on 1pt off 1pt,thin]{
\draw[shorten >=2pt](aton) ..controls +(up:10mm) and +(left:5mm)..(atoc);
\draw[shorten >=8pt](atoo1) ..controls +(up:10mm) and +(north west:10mm)..(atoo2);}
\arrow{<=>[\tiny addition]}
\chemfig{R-@{aton}\chembelow{N}{\scriptstyle\oplus}H([2]-[@{sb}]H)-C(-[2]CH_3)(-[6]CH_3)-OH}
\schemestop
\chemmove{
\draw[-stealth,dash pattern= on 1pt off 1pt,shorten <=3pt, shorten >=2pt]
(sb)..controls +(left:5mm) and +(135:2mm)..(aton);}
\par
\schemestart
\arrow{<=>}
\chemfig{R-@{aton}\charge{90=\|}{N}([6]-[@{sbh}]H)-[@{sb}]C(-[2]CH_3)(-[6]CH_3)-[@{sbo}]@{atoo}
\chemabove{O}{\scriptstyle\oplus}(-[1]H)(-[7]H)}
\chemmove[-stealth,shorten <=3pt,shorten >=2pt,dash pattern= on 1pt off 1pt,thin]{
\draw(aton) ..controls +(up:5mm) and +(up:5mm)..(sb);
\draw(sbh) ..controls +(left:5mm) and +(south west:5mm)..(aton);
\draw(sbo) ..controls +(up:5mm) and +(north west:5mm)..(atoo);}
\arrow{<=>[\tiny elimination]}\chemfig{R-N=C(-[1]CH_3)(-[7]CH_3)}
\+
\chemfig{H_3\chemabove{O}{\scriptstyle\oplus}}
\schemestop
Reaction scheme
\setchemfig{atom sep=2em}
\schemestart[arrow angle=-90]
\chemfig{**6(---(-NH _2)---)}\arrow{0}\chemfig{HNO_2}
\merge(c1)(c2)--()
\chemfig{**6(---(-N_2|{}^\oplus)---)}\arrow{0}\chemfig{**6(---(-NH _2)---)}
\merge(c3)(c4)--()
\chemfig{**6(---(-N=[::-30]N-[::-30]**6(---(-NH_2)---))---)}
\schemestop
Addition
\setchemfig{atom sep=2.5em}
\schemestart
\chemfig{*6(=-(-)(=[2]O))}
\arrow{->[\+\chemfig{H^\oplus}]}
\chemleft[%
\subscheme[90]{%
\chemfig{*6((-[2,0.33,,,draw=none]\scriptstyle\oplus)-=(-)-OH)}
\arrow{<->}
\chemfig{*6(=-(-)(-[6,0.33,,,draw=none]\scriptstyle\oplus)-OH)}}%
\chemright]
\arrow(@c4--)\chemfig{*6(=-(-)(-[6]R)-OH)}
\schemestop
Electrophilic aromatic substitution
\setchemfig{atom sep=1.5em}%
\definesubmol{+}{-[,-0.4,,,draw=none]\oplus}%
\schemestart
\arrow{0}[,0]
\chemleft[\subscheme{\chemfig{*6(=-=-(-[:120]Br)(-[:60]H)-(!+)-)}
\arrow{<->}
\chemfig{*6(-(!+)-=-(-[:120]Br)(-[:60]H)-=)}
\arrow{<->}
\chemfig{*6(-=-(!+)-(-[:120]Br)(-[:60]H)-=)}}\chemright]
\arrow(@c2--){<-[*0\chemfig{{-}AlBr_4|^\ominus}][*0\chemfig{Br_2/Al_2Br_3}]}[90,1.5]
\chemname{\chemfig{*6(-=-=-=-)}}{Benzene 1}
\arrow(@c4--){->[*0\chemfig{{-}H^\oplus}]}[90,1.5]
\chemname{\chemfig{*6(-=-=(-Br)-=-)}}{Bromobenzne 2}
\arrow(@c5.mid east--@c6.mid west)
\schemestop
\chemnameinit{}
Reaction mechanism of chlorination
\scriptsize\setchemfig{bond offset=1pt,atom sep=2em,compound sep=4em}
\schemestart
\chemfig{Cl-[4]@{a0}(=[@{a1}:120]@{a2}O)-[:-120](=[:-60]O)-[4]Cl}\+\chemfig{*6(-=-=(-@{oh1}OH)-=)}\arrow
\chemfig{*6((-O-[:150](-[@{o0}:150]@{o1}\charge{-90=\.}{O})(-[@{cl0}:60]@{cl1}Cl)-[:240](-[4]Cl)=[6]O)=-=-=-)}
\arrow\chemfig{*6((-O-[:150](=[2]O)-[:-150](=[6]O)-[:150]Cl)=-=-=-)}\+\chemfig{HCl}
\arrow(@c1--){0}[-90,0.5]
\chemfig{*6(-=*6(-O-*6(-@{o2}(=[@{o3}]@{o4}O)-Cl)=)-=-=)}\+\chemfig{*6(-=-=(-@{oh2}OH)-=)}\arrow
\chemfig{*6(-=*6(-O-(-(-[@{cl2}:60]@{cl3}Cl)(-[@{o5}:-120]@{o6}\charge{-90=\.}{O})-O-[::-40]*6(=-=-=-))=)-=-=)}
\kern-3em \arrow\chemfig{[:30]*6(=-(-O-[:-60](=O)-[:-120](=[4]O)-[:-60]O-*6(=-=-=-))=-=-)}
\kern-3em \+\chemfig{HCl}
\schemestop
\chemmove[line width=0.2pt,-stealth,dash pattern = on 2pt off 1pt]{
\draw[shorten <=2pt](a1)..controls+(200:5mm)and+(200:5mm)..(a2);
\draw[shorten >=2pt](oh1.west)..controls+(180:15mm)and+(60:5mm)..(a0);
\draw[shorten <=6pt,shorten >=2pt](o1)..controls+(270:5mm)and+(270:5mm)..(o0);
\draw[shorten <=2pt](cl0)..controls+(150:5mm)and+(150:5mm)..(cl1.150);
\draw[shorten <=2pt](o3)..controls +(30:3mm) and +(30:5mm)..(o4.east);
\draw[shorten >=2pt](oh2.135).. controls +(150:10mm) and +(90:10mm).. (o2);
\draw[shorten >=2pt,shorten <=5pt]([xshift=-1.5mm]o6.315)..controls +(315:5mm) and +(315:5mm)..(o5);
\draw[shorten <=2pt](cl2)..controls +(135:5mm) and +(135:5mm)..(cl3.north west);}
Cannizzaro reaction
\schemestart
\chemfig{[:-30]*6(=-=(-@{atoc}C([6]=[@{db}]@{atoo1}O)-H)-=-)}
\arrow(start.mid east--.mid west){->[\chemfig{@{atoo2}\chemabove{O}{\scriptstyle\ominus}}H]}
\chemmove[-stealth,shorten >=2pt,dash pattern=on 1pt off 1pt,thin]{
\draw[shorten <=8pt](atoo2) ..controls +(up:10mm) and +(up:10mm)..(atoc);
\draw[shorten <=2pt](db) ..controls +(left:5mm) and +(west:5mm)..(atoo1);}
\chemfig{[:-30]*6(=-=(-C([6]-[@{sb1}]@{atoo1}\chembelow{O}{\scriptstyle\ominus})([2]-OH)-[@{sb2}]H)-=-)}
\hspace{1cm}
\chemfig{[:-30]*6((-@{atoc}C([6]=[@{db}]@{atoo2}O)-[2]H)-=-=-=)}
\chemmove[-stealth,shorten <=2pt,shorten >=2pt,dash pattern=on 1pt off 1pt,thin]{
\draw([yshift=-4pt]atoo1.270) ..controls +(0:5mm) and +(right:10mm)..(sb1);
\draw(sb2) ..controls +(up:10mm) and +(north west:10mm)..(atoc);
\draw(db) ..controls +(right:5mm) and +(east:5mm)..(atoo2);}
\arrow(@start.base west--){0}[-75,2]
{}
\arrow
\chemfig{[:-30]*6(=-=(-C([1]-@{atoo2}O-[@{sb}0]@{atoh}H)([6]=O))-=-)}
\arrow{0}
\chemfig{[:-30]*6((-C(-[5]H)(-[7]H)-[2]@{atoo1}\chemabove{O}{\scriptstyle\ominus})-=-=-=)}
\chemmove[-stealth,shorten >=2pt,dash pattern=on 1pt off 1pt,thin]{
\draw[shorten <=7pt](atoo1.90) ..controls +(+90:8mm) and +(up:10mm)..(atoh);
\draw[shorten <=2pt](sb) ..controls +(up:5mm) and +(up:5mm)..(atoo2);}
\schemestop
Beckmann rearrangement
\setchemfig{bond offset=1pt,atom sep=2.5em,compound sep=5em,arrow offset=6pt}
\schemestart
\chemfig{(-[:-150]R')(-[:-30]R)=[2]N-[:30]OH}
\arrow{<=>[\chemfig{H^\oplus}]}
\chemfig{(-[@{a0}:-150]R')(-[:-30]R)=[2]@{a1}N-[@{b0}:30]@{b1}\chemabove{O}{\scriptstyle\oplus}H_2}
\chemmove[red,-stealth,red,shorten <=2pt]{
\draw(a0)..controls +(135:2mm) and +(215:4mm).. (a1);
\draw(b0)..controls +(120:2mm) and +(180:3mm).. ([yshift=7pt]b1.180);}
\arrow{<=>[\chemfig{{-}H_2O}]}[,1.1]
\chemleft[\subscheme[90]{%
\chemfig{R'-\chemabove{N}{\scriptstyle\oplus}~C-R}
\arrow{<->}[,0.75]
\chemfig{R'-\charge{90=\:}{N}=@{a1}\chemabove{C}{\scriptstyle\oplus}-R}}\chemright]
\arrow{<=>[\chemfig{H_2@{a0}\charge{0=\:,90=\:}{O}}]}[,1.1]
\chemmove[red,-stealth,red,shorten <=3pt]{
\draw(a0)..controls+(90:10mm)and+(45:10mm)..([yshift=6pt]a1.45);}
\arrow(@c1--){0}[-90,0.333]
\chemfig{*6(R\rlap{$'$}-N=(-R)-\chemabove{O}{\scriptstyle\oplus} H_2)}
\arrow{<=>[\chemfig{{-}H^\oplus}]}
\chemfig{*6(R\rlap{$'$}-N=(-R)-OH)}
\arrow
\chemfig{*6(R\rlap{$'$}-\chembelow{N}{H}-(-R)(=[2]O))}
\schemestop
Reaction scheme
\setchemfig{atom sep=1.5em,compound sep=4em}
\schemestart
\chemfig{-[::30]=_[::-60](-[:: -60])-[::60]}
\arrow{->[\chemfig{HCl}]}
\chemfig{-[::30]-[::-60](-[::120]Cl)(-[::-60])-[::60]}\+\chemfig{-[::30](-[::60]Cl)-[::-60](-[::-60])-[::60]}
\arrow(@c1--.north west){->[\chemfig{H_2O}]}[-45,1.7]
\chemfig{-[::30]-[::-60](-[::120]OH)(-[::-60])-[::60]}\+\chemfig{-[::30](-[::60]OH)-[::-60](-[::-60])-[::60]}
\schemestop
Esterification of formic acid
\tikzset{obrace/.style={left delimiter={[},inner sep=3pt},
cbrace/.style={right delimiter={]},inner sep=3pt},
braces/.style={left delimiter={[},right delimiter={]},inner sep=3pt}}
\setchemfig{atom sep=2em}
\schemestart
\chemfig{H-C(=[:60]O)-[:-60]O-H}
\arrow(--M1[obrace]){-U>[\scriptsize\chemfig{H_2SO_4^{}}][\scriptsize\chemfig{HSO_4^\ominus}][][.25]}%
[,1.5,shorten >=6pt]
\chemfig{H-@{a2}C(-[:60]O-H)(-[:30,.5,,,draw=none]{\scriptstyle\oplus})-[:-60]O-H}
\arrow(--[cbrace]){<->}
\chemfig{H-C(=[:60]\chemabove{O}{\scriptstyle\oplus}-H)-[:-60]O-H}
\arrow(@M1--){<=>[*{0}\scriptsize\chemfig{H-[:120]@{a1}O-[:60]CH_3}][*{0}\tiny addition]}[-90,1.33]
\chemfig{H-C(-[2]O-[:30]H)(-\chemabove{O}{\scriptstyle\oplus}(-[:60]CH_3)-[:-60]H)-[6]O-[:-30]H}
\arrow{<=>[\tiny protolysis]}[180]
\chemfig{H-C(-[2]O-[:30]H)(-O-CH_3)-[@{b1}6]@{a3}\chemabove{O}{\kern-4mm\scriptstyle\oplus}(-[:-150]H)-[:-30]H}
\arrow(--[obrace]){<=>[*{0}\scriptsize\chemfig{{-}H_2O}][*{0}\tiny elimination]}[-90,,shorten >=6pt]
\chemfig{H-C(-[:60]O-H)(-[,.5,,,draw=none]{\scriptstyle\oplus})-[:-60]O-CH_3}
\arrow(--[cbrace]){<->}
\chemfig{H-C(=[:60]\chemabove{O}{\scriptstyle\oplus}-H)-[:-60]O-CH_3}
\arrow{-U>[\scriptsize\chemfig{HSO_4^\ominus}][\scriptsize\chemfig{H_2SO_4^{}}][][.25]}[,1.5]
\chemfig{H-C(=[:60]O)-[:-60]O-CH_3}
\arrow(@M1--[yshift=-5pt]){0}[180,.5]{\tiny protolysis}
\chemmove[red,shorten <=3pt,shorten >=1pt]{
\draw(a1)..controls +(0:1.5cm)and+(0:3cm).. (a2);
\draw(b1)..controls +(0:5mm)and+(20:5mm)..(a3);}
\schemestop
Electrophilic addition of halogen to olefin
\schemestart
\subscheme{%
\chemfig{C(<[:40])(<[:160])=[6]C(<[:-130])<[:-20]}
\arrow{0}[,0]\+\chemfig{\charge{90=\|,180=\|,270=\|}{Br}-\charge{90=\|,0=\|,270=\|}{Br}}}
\arrow(@c1--olefin){<=>[*{0}rapide]}[-90]
\chemfig{>[:-20]C(<[:40])=[@{db}6]C(<[:-130])<[:-20]}
\arrow(--bromonium){0}[-90]
\chemname{\chemfig{C*3((<)(<:[:-155])-\charge{45=\|,-45=\|,180:3pt=$\scriptstyle\oplus$}{Br}-C(<:)(<[:155])-)}}
{bromonium ion}
\arrow(--carbeniumA){<<->}[,1.5]
\chemname{\chemfig{-[:-30]\chemabove{C}{\scriptstyle\oplus}(-[:30])-[6]C(<:[:-150])(<[:-100])-[:-30]
\charge{45=\|,-45=\|,225=\|}{Br}}}{Xarbenium ion}
\arrow(@bromonium--carbeniumB){<<->}[180,1.5]
\chemname{\chemfig{-[:-30]\chemabove{C}{\scriptstyle\oplus}(-[:30])-[6]C(<[:-150])
(<:[:-100])-[:-30]\charge{45=\|,-45=\|,135=\|}{Br}}}{carbenium ion}
\arrow(@olefin--){0}[,.25]
\chemfig{@{Br1}\charge{90=\|,180=\|,270=\|,90:5pt=$\scriptstyle\delta\oplus$}{Br}-[@{b2}]@{Br2}
\charge{90=\|,0=\|,270=\|,90:5pt=$\scriptstyle\delta\ominus$}{Br}}
\arrow(@olefin--[left]){0}[180,0]
$\pi$ complexe
\arrow(@carbeniumA--@olefin){<=>[lent, \chemfig{{-}Br^\ominus}]}
\arrow(@carbeniumB--@olefin){<=>[lent, \chemfig{{-}Br^\ominus}]}
\chemmove[-stealth,red,shorten <=3pt,shorten >=2pt]{
\draw(db) .. controls +(20:5mm) and +(135:5mm) .. (Br1);
\draw(b2) .. controls +(-90:5mm) and +(-120:5mm) .. (Br2);}
\schemestop
\chemnameinit{}
Sulfonation of naphthalene
\definesubmol\cycleoplus{-[,0.25,,,draw=none]\oplus}
\definesubmol{so2oh}{S(=[::90]O)(=[::-90]O)-OH}
\setchemfig{atom sep=2.5em}
\schemestart[arrow coeff=1.5]
\chemname{\chemfig{*6(=-*6(-=-=-)=-=-)}}{Naphtalene}\+\chemfig{H_2SO_4}
\arrow(nph.mid east--.south west){->[80\degres C]}[45]
\chemname{\chemfig{*6(=-*6(-=-(!\cycleoplus)-(-SO_3H)-)=-=-)}}{Ion 1-arenium}
\arrow(.mid east--.mid west)
\chemname{\chemfig{*6(=-*6(-=-=(-!{so2oh})-)=-=-)}}{Acide 1-naphthalenesulfonique}
\arrow(@nph.mid east--.north west){->[160\degres C]}[-45]
\chemname{\chemfig{*6(=-*6(-=-(-SO_3H)-(!\cycleoplus)-)=-=-)}}{Ion 2-arenium}\kern-4em
\arrow(.mid east--.mid west)
\chemname{\chemfig{*6(=-*6(-=-(-!{so2oh})=-)=-=-)}}{Acide 2-naphthalenesulfonique}
\schemestop
\chemnameinit{}
Taxotere
\chemfig{-[::-30](-[5])(-[7])-[::+60]-[::-60]O-[::+60](=[::-45]O)-[::+90]HN>:[::-60](-[::+60]**6(------))
-[::-30](<:[2]OH)-[::-60](=[6]O)-[::+60]O>:[::-60]*7(---?(<[::-120]OH)-(<|[1]CH_3)(<:[::-90]CH_3)
-(-[1](<[::+80]HO)-[0](=[::+60]O)-[7](<|[::+130]CH_3)(-[::+75](<|[2]OH)-[::-60]-[::-60](<[::+30]O-[::-90])
-[::-60](<[::+90])(<:[::+30]O-[7](-[6]CH_3)=[0]O)-[::-60])-[6]-[5,1.3]?(<:[7]O-[5](=[::-60]O)
-[6]**6(------)))=(-[2]CH_3)-)}
Diverging arrows
\schemestart
\chemfig{(-[:210]R_2)(-[:330]R_1)=[2]O}
\arrow(a--)[,1.5,,,draw=none]
\subscheme{
\charge{30:4pt=$\mathrm{S}_1$}{\chemleft{[}\chemfig{(-[:210]R_2)(-[:330]R_1)=[2]O}\chemright{]}}
\arrow(b--c){->[*{0}ISC]}[-90,1.5]
\charge{30:4pt=$\mathrm{T}_1$}{\chemleft[\chemfig{(-[:210]R_2)(-[:330]R_1)=[2]O}\chemright{]}}
}
\arrow(--d)[,1.5,,,draw=none]
\chemfig{(-[:210]R_2)(-[:330,0.1,,,draw=none]\charge{330:-1pt=\.\,}{})=[2]O}
\+
\chemfig{\charge{90:1pt=\.\,}{R}_1}
\schemestop
\chemmove{
\draw[thick,shorten >=10pt] (a.east) -- ++(1,0) |- (b.west);
\draw[thick,shorten >=10pt] (a.east) -- ++(1,0) |- (c.west);
\draw[-,thick,shorten >=15pt,shorten <=8pt] (b.east) -- ++(1.3,0) |- (d.west);
\draw[thick,shorten >=10pt,shorten <=8pt] (c.east) -- ++(1.3,0) |- (d.west);
}