Ternary complexes of vanadium(IV) with 4-(2-pyridylazo)-resorcinol (PAR) and ditetrazolium chlorides (DTC)
Küçük Resim Yok
Tarih
2010
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Versita
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Complex formation and liquid-liquid extraction have been studied for ternary complexes of vanadium(IV) with 4-(2-pyridylazo)-resorcinol (PAR) and ditetrazolium chlorides (DTC) in a water-chloroform medium. The specific ditetrazolium compounds investigated were i) 3,3'-(4,4'-biphenylene)-bis(2,5-diphenyl-2H-tetrazolium) chloride (Neotetrazolium chloride, NTC); ii) 3,3'-(3,3'-dimetoxy-4,4'-biphenylene)-bis(2,5-diphenyl-2H-tetrazolium) chloride (Blue Tetrazolium chloride, BTC); and iii) 3,3'-(3,3'-dimetoxy-4,4'-biphenylene)bis[2-(4-nitrophenyl)-5-phenyl-2H-tetrazolium] chloride (Nitro Blue Tetrazolium chloride, NBT). Molar absorptivity coefficients and the composition of the complexes have been calculated. Association constants (beta) have also been obtained for the interactions between the vanadium(IV) - PAR anionic chelates [VO(PAR)(2)](2-) (I) and [VO(OH)(2)(PAR)(2)](4-) (II), and ditetrazolium cations (DT2+). Some special features of NBT as an extraction-spectrophotometric reagent for vanadium(IV) have been discussed. Unlike NTC and BTC which form complexes with both I and II, NBT associates only with II. The pH interval for complete extraction of (NBT(2+))(2)[VO(OH)(2)(PAR)(2)] is broader and allows work at lower pH values the other ion-associates of V(IV, V)-PAR that were studied. NBT is -therefore the appropriate reagent both for direct V(IV) determination and for V(IV)/V(V) separation. Some additional characteristics for the V(IV)-PAR-NBT-water-chloroform system have been determined: extraction constant, distribution constant, recovery factor, limit of detection and limit of quantification. Beer's law is valid up to 1.4 mu g mL(-1) vanadium(IV) with molar absorptivity coefficient of 3.55 x 10(4) L mol(-1) cm(-1) at lambda(max)=559 nm.
Açıklama
Anahtar Kelimeler
Vanadium(IV), Nitro Blue Tetrazolium, Ion-Associate Complex, Liquid-Liquid Extraction, Spectrophotometry, Extractive-Spectrophotometric Determination, Environmental-Samples, Speciation Analysis, Tetrazolium Salts, Anionic Chelate, Plant Materials, 4-(2-Pyridylazo)Resorcinol, Violet, Water, Acid
Kaynak
Central European Journal Of Chemistry
WoS Q Değeri
Q3
Scopus Q Değeri
N/A
Cilt
8
Sayı
2
