二溴对甲基偶氮羧质子化及其离解

用萃取法对二溴对甲基偶氮羧进行了纯化,并用分光光度法研究了二溴对甲基偶氮羧的质子化和五级离解作用,测定了其质子化常数和逐级离解常数,获得满意的效果。     

氯磺酚S与蛋白质作用的分光光度研究

在ＰＨ２．４的Ｃｌａｒｋ－Ｌｕｂｓ缓冲介质中,氯磺酚Ｓ与蛋白质能形成复合物,最大吸收峰的波长为６３２ｎｍ,比试剂本身红移约８０ｎｍ,实验制定的几种蛋白质的工作曲线一范围较宽,灵敏度较高,用于人血清样品测定的准确度高、干扰少。本方法中试剂及反应体系稳定。分析手续简便经济。     

分析量子化学研究(Ⅱ)——光度分析新显色剂对甲基偶氮氯膦离解与质子化作用及其机理

对甲基偶氮氯膦(CPApM)作为不对称偶氮氯膦类光度分析显色剂,已应用于稀土氧化物与有关矿石、镍基合金中测定钇的含量,本文以分光光度法测得了CPApM的离解常数及质子化常数,运用HMO法进行半经验量子化学计算,并对其电子结构、离解作用与质子化作用及微观机理作了探讨。     

血清蛋白质与氯磺酚K反应及其分析应用的研究

发现有机小分子氯磺酚K与生物活性物质蛋白质能发生染色反应 ,在pH4.30的缓冲溶液中 ,红色的氯磺酚K与无色的牛血清白蛋白形成蓝紫色复合物 ,其最大吸收波长为624nm ,较试剂本身红移约74nm ,表观摩尔吸光系数达2.49×105L·mol -1·cm -1,线性范围为0～240μg/mL。实验制定的几种蛋白质的工作曲线 ,其灵敏度和线性范围与牛血清白蛋白基本一致 ,用于临床中人血清蛋白质的测定 ,结果令人满意。     

间氯偶氮安替比林的纯化鉴定及其离解常数和质子化常数的测定

本文研究提出了适合于新显色剂间氯偶氮安替比林的纯化新方法,经该方法纯化后的试剂在纸色谱图上仅有一个斑点,元素分析结果也令人满意。经过元素分析、热重分析和红外吸收光谱的测定,进一步确定了试剂的组成和结构。首次用光度法测定了试剂的离解常数(pKa=7.35±0.03)和质子化常数(1ogKp=-3.50±0.17)。     

质子化和脱质子化对酞菁光谱的影响

系统地研究四异丙氧基酞菁的子化和脱质子化对吸收和发射光谱的影响，研究表明，三氟乙酸可对酞菁分子连续质子化，分别生成（Ｈ２Ｐｃ（Ｏ＾ｉＰｒ）４．Ｈ＾＋）＾和（Ｈ２Ｐｃ（Ｏ＾ｉＰｒ）４．２Ｈ＾＋）＾２＋，而硫酸可使酞菁形成（Ｈ２Ｐｃ（Ｏ＾ｉＰｒ）４．４Ｈ＾＋＾４＋此外，ＮａＯＨ／ＥｔＯＨ可使酞菁分子脱质子化生成（Ｐｃ（Ｏ＾ｉＰｒ）４）＾２－反应一步完成，表明分子中的两个吡咯－ＮＨ－同步酸解，质子化可使     

The Determination of the Protonation Constants of A New Macrocyclic Dinucleating Ligand, BDBPH

One of our current interests focuses on the design and synthesis of polyaza macrocyclic ligands, the determination of their protonation constants, and the stabilities of corresponding metal complexes. Two polyazadiphenol macrocycles, R(babp)2(dfc)21 and [24]RBPyBC2, one octaazamacrocycle, BPBD3,4, and several hexaaza macrocyclic ligands, BFBD5, BMXD6, and OBISDIEN7, have been reported recently. We have also reported the synthesis of a new dinucleating 24-membered hexaazadiphenol macr…     

Protonation and deprotonation of hydroxamic acids. An MO ab initio study

Ab initio molecular orbital calculations with 4-31G//4-31G, 6-31G^*//4-31G and 6-31+G//4-31G basis sets have been used to examine the structure, relative energy, protonation and deprotonation of a series of seven hydroxamic acids in the gas phase. The results show that hydroxamic acids are predominantly in the E-TS form and that the most probable protonation site is the carbonyl oxygen atom, while deprotonation proceeds by loss of NH hydrogen.     

离子色谱法测定一元弱酸的离解常数

本文探索了抑制电导离子色谱法测定pK_a<7的一元弱酸的离解常数,对以HCl为标准测定HF、HNO_2的离解常数和以HF为标准测定乳酸、乙酸和甲酸的离解常数及测定方法的主要误差来源进行了讨论。     

Protonation of manganese phosphonioallenyl complexes

The addition of phosphines to the manganese allenylidene complexes Cp(CO)₂MnCCC(Ph)R (R = H, Ph) proceeds selectively at the C_α atom to result in the α-phosphonioallenyl complexes Cp(CO)₂Mn⁻-C(⁺PR₃¹)CC(Ph)R. The protonation of the latter affords the η²-(1,2)-phosphonioallenes Cp(CO)₂Mn{η²-(1,2)-HC(⁺PR₃¹)CC(Ph)R}, rather than the phosphoniovinylcarbenes Cp(CO)₂MnC(⁺PR₃¹)-HCC(Ph)R. All complexes obtained are stereochemically rigid and do not isomerize into the η²-(2,3)-phosphonioallene isomers.     

Protonation of 25,27-bis(1-octyloxy)calix[4]arene-crown-6 in the 1,3-alternate conformation

From extraction experiments in the two-phase water-nitrobenzene system and γ-activity measurements, the stability constant of protonated 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6 in nitrobenzene saturated with water was determined. By using DFT calculations, the most probable structure of the 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6 · H₃O⁺ complex species was derived. Correspondence: Emanuel Makrlík, Faculty of Applied Sciences, University of West Bohemia, Pilsen, Czech Republic.     

Enantioselective Protonation of Enolates and Enols

Enantioselective protonation, until recently a largely overlooked reaction, has, in the last five years, developed into a field of intense research activity. The progress achieved parallels or complements that obtained in the understanding of enolate structures and reactivities. The conceptual simplicity and attractiveness of enantioselective protonation results from the fact that after reaction, the chiral proton donor is regenerated in its original protonated form by an extractive workup. Enantioselective protonation has been applied to the synthesis of amino acids, antiinflammatory agents (2-arylpropanoic acids), and fragrance compounds such as (S)-α-damascone, for which its industrial feasibility has been demonstrated.     

Reactions of metalloalkynes VII. Protonation of ruthenium ethyne-1,2-diyl complexes

The acid–base chemistry of some ruthenium ethyne-1,2-diyl complexes, [{Ru(CO)₂(η-C₅H₄R)}₂(μ₂-CC)] (R=H, Me) has been investigated. Initial protonation of [{Ru(CO)₂{η-C₅H₄R}}₂(μ₂-CC)] gave the unexpected complex cation, crystallised as the BF₄ salt, [{Ru(CO)₂(η-C₅H₄R}}₃(μ₃-CC)][BF₄] (R=Me structurally characterised). This synthesis proved to be unreliable but subsequent, careful protonation experiments gave excellent yields of the protonated ethyne-1,2-diyl complexes, [{Ru(CO)₂{η-C₅H₄R)}₂(μ₂-η¹:η²-CCH)](BF₄) (R=Me structurally characterised) which could be deprotonated in high yield to return the starting ethyne-1,2-diyl complexes.