4-Mercaptobenzoic acid
{{Chembox
| ImageFile = 4-mercaptobenzoic acid.svg
| ImageSize = 180px
| ImageAlt = Skeletal formula of 4-mercaptobenzoic acid
| IUPACName = 4-sulfanylbenzoic acid
| OtherNames =
|Section1 = {{Chembox Identifiers
| CASNo = 1074-36-8
| CASNo_Ref = {{Cascite|correct|CAS}}
| ChEMBL = 98938
| ChemSpiderID = 86425
| EC_number = 600-825-1
| PubChem = 95738
| StdInChI=1S/C7H6O2S/c8-7(9)5-1-3-6(10)4-2-5/h1-4,10H,(H,8,9)
| StdInChIKey = LMJXSOYPAOSIPZ-UHFFFAOYSA-N
| SMILES = C1=CC(=CC=C1C(=O)O)S
}}
|Section2 = {{Chembox Properties
| C=7|H=6|O=2|S=1
| Formula =
| MolarMass =
| Appearance =
| Density =
| MeltingPtC = 215–224
| BoilingPt =
| Solubility =
}}
|Section3={{Chembox Hazards
| GHS_ref= {{Sigma-Aldrich|id=706329|name=4-Mercaptobenzoic acid|accessdate=11 January 2025}}
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|315|319|335}}
| PPhrases = {{P-phrases|P261|P264|P271|P280|P302 + P352|P305 + P351 + P338}}
}}
|Section8={{Chembox Related
| OtherAnions =
| OtherCations =
| OtherFunction_label =
| OtherFunction =
| OtherCompounds = {{ubl|2-mercaptobenzoic acid|{{ill|3-mercaptobenzoic acid|qid=Q18472709}}}}
}}
}}
4-Mercaptobenzoic acid (p-mercaptobenzoic acid, p-MBA) is an organosulfur compound with the formula para-{{chem2|C6H4(\sSH)(\sCOOH)}}. It is used as a ligand in thiolate-protected gold cluster compounds, such as {{chem2|Au102(p\-MBA)44}}.{{cite journal |last1=Ackerson |first1=Christopher J. |last2=Jadzinsky |first2=Pablo D. |last3=Kornberg |first3=Roger D. |author-link3=Roger D. Kornberg |title=Thiolate Ligands for Synthesis of Water-Soluble Gold Clusters |journal=Journal of the American Chemical Society |date=1 May 2005 |volume=127 |issue=18 |pages=6550–6551 |doi=10.1021/ja046114i|bibcode=2005JAChS.127.6550A }}{{cite journal |last1=Levi-Kalisman |first1=Yael |last2=Jadzinsky |first2=Pablo D. |last3=Kalisman |first3=Nir |last4=Tsunoyama |first4=Hironori |last5=Tsukuda |first5=Tatsuya |last6=Bushnell |first6=David A. |last7=Kornberg |first7=Roger D. |author-link7=Roger D. Kornberg |title=Synthesis and Characterization of Au102(p-MBA)44 Nanoparticles |journal=Journal of the American Chemical Society |date=9 March 2011 |volume=133 |issue=9 |pages=2976–2982 |doi=10.1021/ja109131w|bibcode=2011JAChS.133.2976L }}