成人免费xx,国产又黄又湿又刺激不卡网站,成人性视频app菠萝网站,色天天天天

3,4-Dihydroxy-3-cyclobuten-1,2-dion

Squaric acid Struktur
2892-51-5
CAS-Nr.
2892-51-5
Bezeichnung:
3,4-Dihydroxy-3-cyclobuten-1,2-dion
Englisch Name:
Squaric acid
Synonyma:
3,4-DIHYDROXY-3-CYCLOBUTENE-1,2-DIONE;3,4-DIHYDROXYCYCLOBUT-3-ENE-1,2-DIONE;2-dione;Squaric;NSC 624671;squaricaci;SQUARC ACID;SQUARIC ACID;QUADRATIC ACID;obutene-1,2-dione
CBNumber:
CB6263069
Summenformel:
C4H2O4
Molgewicht:
114.06
MOL-Datei:
2892-51-5.mol

3,4-Dihydroxy-3-cyclobuten-1,2-dion Eigenschaften

Schmelzpunkt:
>300 °C(lit.)
Siedepunkt:
250.96°C
Dichte
1.82 g/cm3
Brechungsindex
1.5800 (estimate)
Flammpunkt:
190 °C
storage temp. 
Inert atmosphere,Room Temperature
L?slichkeit
20g/l
pka
1.5??(at 25℃)
Aggregatzustand
Crystalline Powder
Farbe
White to beige
PH
1 (1g/l, H2O, 20℃)
Wasserl?slichkeit
20 g/L (30 ºC)
Merck 
14,8769
BRN 
774275
InChIKey
PWEBUXCTKOWPCW-UHFFFAOYSA-N
CAS Datenbank
2892-51-5(CAS DataBase Reference)
NIST chemische Informationen
3-Cyclobutene-1,2-dione, 3,4-dihydroxy-(2892-51-5)
EPA chemische Informationen
3-Cyclobutene-1,2-dione, 3,4-dihydroxy- (2892-51-5)
Sicherheit
  • Risiko- und Sicherheitserkl?rung
  • Gefahreninformationscode (GHS)
Kennzeichnung gef?hrlicher Xi
R-S?tze: 36/37/38-43
S-S?tze: 26-36-37/39
RIDADR  3261
WGK Germany  3
RTECS-Nr. GU1800000
Hazard Note  Irritant
TSCA  Yes
HazardClass  8
PackingGroup  II
HS Code  29144090
Bildanzeige (GHS) GHS hazard pictograms
Alarmwort Achtung
Gefahrenhinweise
Code Gefahrenhinweise Gefahrenklasse Abteilung Alarmwort Symbol P-Code
H314 Verursacht schwere Ver?tzungen der Haut und schwere Augensch?den. ?tzwirkung auf die Haut Kategorie 1B Achtung GHS hazard pictogramssrc="/GHS05.jpg" width="20" height="20" /> P260,P264, P280, P301+P330+ P331,P303+P361+P353, P363, P304+P340,P310, P321, P305+ P351+P338, P405,P501
Sicherheit
P260 Dampf/Aerosol/Nebel nicht einatmen.
P280 Schutzhandschuhe/Schutzkleidung/Augenschutz tragen.
P301+P330+P331 BEI VERSCHLUCKEN: Mund ausspülen. KEIN Erbrechen herbeiführen.
P303+P361+P353 BEI BERüHRUNG MIT DER HAUT (oder dem Haar): Alle kontaminierten Kleidungsstücke sofort ausziehen. Haut mit Wasser abwaschen oder duschen.
P305+P351+P338 BEI KONTAKT MIT DEN AUGEN: Einige Minuten lang behutsam mit Wasser spülen. Eventuell vorhandene Kontaktlinsen nach M?glichkeit entfernen. Weiter spülen.

3,4-Dihydroxy-3-cyclobuten-1,2-dion Chemische Eigenschaften,Einsatz,Produktion Methoden

R-S?tze Betriebsanweisung:

R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R43:Sensibilisierung durch Hautkontakt m?glich.

S-S?tze Betriebsanweisung:

S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S37/39:Bei der Arbeit geeignete Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.

Chemische Eigenschaften

Squaric acid (3,4-dihydroxycyclobut-3-ene-1,2-dione), also known as quadratic acid, has the fascinating structure, and is a vinylogous carboxylic acid. The parent compound is a white,crystalline powder which melts at~300℃. It is highly acidic (pKa 1.5 for the first proton and 3.4 for the second) due to resonance stabilization of the anion and exhibits IR resonances indicative of strong hydrogen bonding [2326cm-1 (OH),1818 cm-1 (C=O), and 1639cm-1 (C=C)].The UV absorption spectrum suggests that the acid is essentially completely ionized. Squaric acid is freely soluble in water but has poor solubility in many organic solvents.Solutions give an intense purple color with iron(III) chloride, and are also known to decolorize bromine water, cerium(IV) nitrate, and permanganate solutions.As the carbonyl groups are similar to those of carboxylic acids rather than those of ketones, squaric acid does not react in the phenylhydrazine test.The squarate dianion is thought to be completely symmetrical (unlike squaric acid itself), with all C-C and C-O bond lengths being, respectively, identical, as the negative charges are equally distributed between allthe oxygen atoms.The IR spectrum of dipotassium squarate (dipotassium 3,4-dioxocy-clobut-1-ene-1,2-diolate) differs greatly from that of squaric acid, with the loss of the car-bonyl (C=O) and alkene(C=C) absorptions seen in the protonated form, and supportsthe proposed symmetrical structure.

Verwenden

Squaric acid used as intermediate for squaraine dyes and heterocycles. Squaric acid is an immunotherapy used to treat common warts. This treatment is non-toxic, and easy to use. The treatment activated your immune system to combat the warts and therefore it may cause an allergic reaction , similar to poison oak. This reaction can be managed with a topical cortisone cream. Blistering and lightening of the skin may occur, but rarely.
Squaric acid derivatives – synthetic targets for ring expansion reactions

Definition

ChEBI: A carbon oxoacid that consists of 1,2-diketocyclobut-3-ene bearing two enolic hydroxy substituents at positions 3 and 4.

Allgemeine Beschreibung

3,4-dihydroxy-3-cyclobutene-1,2 dione, commonly known as squaric acid, is widely used in bioorganic and medicinal chemistry. It is an inhibitor of glyoxylase, semiqauric acid, pyruvate dehrogenase, and transketolase. It is used as a replacement for phosphate in a peptide-based ligand for an SH2 domain. Its derivatives are high-affinity ligands for excitatory amino acid receptors. These derivatives are also used as dyes for fluorescence detection of small biological molecules.

Biotechnological Applications

squaric acid is widely used in bioorganic and medicinal chemistry. It is an inhibitor of glyoxylase, semiqauric acid, pyruvate dehrogenase, and transketolase. It is used as a replacement for phosphate in a peptide-based ligand for an SH2 domain. Its derivatives are high-affinity ligands for excitatory amino acid receptors. These derivatives are also used as dyes for fluorescence detection of small biological molecules.
squaric acid can be used:
In fluorescence detection in immunoassays, hybridization assays, enzymatic reactions, and other analytical procedures.
To form diffraction quality crystals.
To synthesize a squarate dianion, which is used as a building block to create uncharged polymeric networks. These ordered structures are used in catalysis, nonlinear optics, electrical conductivity, molecular recognition, and molecular sieves.

l?uterung methode

Purify squaric acid by recrystallisation from H2O — this is quite simple because the acid is ~ 7% soluble in boiling H2O and only 2% at room temperature. It is not soluble in Me2CO or Et2O; hence it can be rinsed with these solvents and dried in air or a vacuum. It is not hygroscopic and gives an intense purple colour with FeCl3. It has IR max at 1820 (C=O) and 1640 (C=C) cm-1, and UV max at 269.5nm ( 37K M-1cm -1). [Cohn et al. J Am Chem Soc 81 3480 1959, Park et al. J Am Chem Soc 84 2919 1962] See also pKa values of 0.59 ±0.09 and 3.48 ±0.023 [Scwartz & Howard J Phys Chem 74 4374 1970]. [Schmidt & Reid Synthesis 869 1978, Beilstein 8 IV 2701.]

3,4-Dihydroxy-3-cyclobuten-1,2-dion Upstream-Materialien And Downstream Produkte

Upstream-Materialien

Downstream Produkte


3,4-Dihydroxy-3-cyclobuten-1,2-dion Anbieter Lieferant Produzent Hersteller Vertrieb H?ndler.

Global( 451)Lieferanten
Firmenname Telefon E-Mail Land Produktkatalog Edge Rate
SHANDONG OUCHEM CO.,LTD.
+86-18506360988 +86-18506360988
wtaili@ouchem.cn China 51 58
Hebei Mojin Biotechnology Co., Ltd
+86 13288715578 +8613288715578
sales@hbmojin.com China 12835 58
Hebei Yanxi Chemical Co., Ltd.
+8617531190177
peter@yan-xi.com China 5857 58
Shaanxi Haibo Biotechnology Co., Ltd
+undefined18602966907
qinhe02@xaltbio.com China 997 58
Henan Fengda Chemical Co., Ltd
+86-371-86557731 +86-13613820652
info@fdachem.com China 20284 58
Hebei Zhuanglai Chemical Trading Co.,Ltd
+8613343047651
admin@zlchemi.com China 3002 58
Hebei Shengyang Water Conservancy Engineering Co., Ltd.
+8615373025980
clara@hbshengyang.com China 875 58
Springchem New Material Technology Co.,Limited
+86-021-62885108 +8613917661608
info@spring-chem.com China 2068 57
Capot Chemical Co.,Ltd.
+86-(0)57185586718 +86-13336195806
sales@capot.com China 29791 60
Henan Tianfu Chemical Co.,Ltd.
+86-0371-55170693 +86-19937530512
info@tianfuchem.com China 21634 55

2892-51-5(3,4-Dihydroxy-3-cyclobuten-1,2-dion)Verwandte Suche:


  • 4-dihydroxy-3-cyclobutene-1
  • 3,4-Dihydroxy-3-cyclobuten-1,2-dion
  • 3,4-Dihydroxy-3-cyclobutene-1,2-dione, 99% 25GR
  • 3,4-Dihydroxy-3-cyclobutene-1,2-dione, 99% 5GR
  • dihydroxy-cyclobutenedion
  • dihydroxycyclobutenedione
  • 3,4-DIHYDROXY-3-CYCLOBUTEN-1,2-DIONE
  • 1-Cyclobutene-3,4-dione-1,2-diol Squaric Acid
  • 1,2-DIHYDROXY-3,4-CYCLOBUTENEDIONE FOR S
  • NSC 624671
  • dihydroxycyclobut-3-ene-1,2-dione
  • Squaric acid, 1,2-Dihydroxy-3,4-dioxocyclobut-1-ene
  • 3,4-Dihydroxy-3-cyclobutene-1,2-dione 99%
  • 3,4-Dihydroxy-3-cyclobutene-1,2-dione 3,4-Dihydroxycyclobut-3-ene-1,2-dione
  • 1-Cyclobutene-3,4-dione-1,2-diol 3,4-Dihydroxy-3-cyclobutene-1,2-dione
  • 1,2-Dihydroxy-3,4-cyclobutenedione for synthesis
  • 1,2-Dihydroxycyclobutene-3,4-dione
  • 1,2-Diketo-3,4-dihydroxycyclobutene
  • 3,4-dihydroxy-3-cyclobutene-2-dione
  • 3,4-Dihydroxy-cyclobutene-1,2-dione
  • 3,4-dihydroxy-cyclobutene-2-dione
  • 3-Cyclobutene-1,2-dione,3,4-dihydroxy-
  • Cyclobutene-1,2-dione, 3,4-dihydroxy-
  • Cyclobutenedione, dihydroxy-
  • 1,2-DIHYDROXY-1-CYCLOBUTEN-3,4-DIONE
  • 1,2-DIHYDROXY-3,4-CYCLOBUTENEDIONE
  • 1,2-DIHYDROXY CYCLOBUTENEDIONE
  • 1-CYCLOBUTENE-3,4-DIONE-1,2-DIOL
  • QUADRATIC ACID
  • SQUARIC ACID
  • DIKETOCYCLOBUTENEDIOL
  • TIMTEC-BB SBB007891
  • 3,4-DIHYDROXY-3-CYCLOBUTENE-1,2-DIONE, 9 9%
  • 3,4-Dihdroxy-3-Cyclobutene-1,2-Dione
  • 3,4-DIHYDROXY-3-CYCLOBUTENE-1,2-DIONE(SQUARIC ACID)
  • SQUARC ACID
  • SQUARIC ACID (3,4-DIHYDROXY-3-CYCLOBUTENE-1,2-DIONE)
  • 3,4-Dihydroxy-3-cyclobutan-1,2-dione
  • SQUARICACIDDIBUTYLESTERS
  • 3,4-Dihydroxy-3-cyclobutene-1,2-dione, 98+%
  • 3,4-Dihydroxy-3-cycL
  • obutene-1,2-dione
  • 3,4-Dihydroxy-3-cyclobutene-1,2-dione, 99%, for synthesis
  • 3,4-Dihydroxy-3-cyclobutene-1,2-dione >
  • squaricaci
  • 2892-51-5 3,4-Dihydroxy-3-cyclobutene-1,2-dione
  • 1,2-DIHYDROXY-1-CYCLOBUTEN-3,4-DI
  • 2-dione
  • 3,4-DIHYDROXY-3-CYCLOBUTENE-1,2-DIONE
  • 3,4-DIHYDROXYCYCLOBUT-3-ENE-1,2-DIONE
  • Squaric
  • 2892-51-5
  • 2892-51-4
  • 2832-51-5
  • HO2C4O2
  • C4H2O4
  • Organic Building Blocks
  • Ketones
Copyright 2019 ? ChemicalBook. All rights reserved