p-XYLYLENEDITHIOL

PRODUCT IDENTIFICATION
CAS NO. 105-09-9

p-XYLYLENEDITHIOL

EINECS NO. 203-269-4
FORMULA C8H10S2
MOL WT. 170.29

H.S. CODE

 2930.90

TOXICITY

  
SYNONYMS 1,4-Bis(mercaptomethyl)benzene;
p-Xylenedithiol; p-Xylene-alpha,alpha'-dithiol; 1,4-Benzenebis(methanethiol); p-Xylol-alpha, alpha'-dithiol; p-Xileno-alpha,alpha'-ditiol (Spanish); p-Xylène-alpha,alpha'-dithiol (French);
SMILES

 

CLASSIFICATION

  

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE white to yellow solid
MELTING POINT

50 - 55 C

BOILING POINT

156 C at 12 mm Hg

SPECIFIC GRAVITY

 

SOLUBILITY IN WATER  
pH  
VAPOR DENSITY

 

AUTOIGNITION  

REFRACTIVE INDEX

  
NFPA RATINGS  
FLASH POINT

 

STABILITY Stable under normal conditions. Light, air sensitive

APPLICATIONS
Mercaptan: any of a class of organosulfur compounds is similar to the alcohol and phenol but containing a sulfur atom in place of the oxygen atom. Compounds containing -SH as the principal group directly attached to carbon are named 'thiols'. In substitutive nomenclature their names are formed by adding '-thiol' as a suffix to the name of the parent compound. When -SH is not the principal group, the prefix 'mercapto-' is placed before the name of the parent compound to denote an unsubstituted -SH group. 'thio'  is a chemical prefix indicates the replacement of an oxygen in an acid radical by sulfur with a negative valence of 2. Sulfur analog of alcohol is called thiol (or mercaptan), and ether analog is called sulfide.

The first chemical contrast of thiols and sulfides with alcohols and ethers is acidity which is important in organic reactions. Thiols are stronger acids than relevant alcohols and phenols. Thiolate conjugate bases are easily formed, and are excellent nucleophiles in SN2 reactions of alkyl halides and tosylates. The nucleophilicity of sulfur is much greater than that of oxygen, resulting in a number of useful electrophilic substitution reaction that are rare by oxygen. For example, sulfides form (with alkyl halides) ternary sulfonium salts, in the same alkylattion of tert-amines quaternary ammonium salts, whereas ternary oxonium salts are prepared only under extream conditions. Without exception, sulfoxides, sulfinate salts and sulfite anion also alkylate on sulfur, despite of the partial negative formal charge on oxygen and partial positive charge on sulfur. The second character is the oxidation states of sulfur. Oxygen has only two oxidation states, whereas sulfur covers from –2 to +6 as follows:

  • -2: Hydrogen Sulfide (H2S), sulfides, sulfonium ions
  • -1: disulfides
  • 0: S elemental, sulfoxides, sulfenic acids
  • +2: sulfones, sulfinic acids
  • +4: sulfonic acids, sulfite esters
  • +6: sulfate esters

One more sulfur compound's contrast with oxygen analog is in oxidation chemistry. Oxidation of sulfur compounds changes the oxidation state of sulfur rather than carbon, whereas, oxidation of  alcohols to aldehydes and ketones changes the oxidation state of carbon not oxygen. Thiols is oxidized to S-S single bond (disufide) which is stronger than O–O bond in peroxide. Disufide forms sulfenyl chlorides (with chlorine in mild condition) or sulfonic acids under harder condition. Oxidation of sulfides with hydrogen peroxide (or peracids) yields sulfoxides and then to sulfones. A certain sulfoxide compound such as dimethyl sulfoxide can be used as an effective oxygen source in the oxidation reaction of primary and secondary alcohols to aldehydes and ketones. DMSO easily is reduced to dimethyl sulfide and water is taken up by the electrophile. oxidation procedure is very mild and tolerates a variety of other functional groups, including those having oxidizable nitrogen and sulfur atoms.

p-Xylylenedithiol is used as an intermediate for manufacturing synthetic organic compounds, pharmaceuticals, colorants and agrochemicals.
SALES SPECIFICATION

APPEARANCE

 white to pale yellow powder

ASSY

97.0% min
MELTING POINT

50 - 55 C
TRANSPORTATION
PACKING
 
HAZARD CLASS not regulated
UN NO.  
OTHER INFORMATION
Hazard Symbols: XI. Risk Phrases: 36/37/38, Safety Phrases: 26-37/39