Potassium nitrite appears as a yellowish white crystalline solid. Noncombustible but accelerates the burning of all combustible material. If large quantities are involved in fire or if the combustible material is finely divided, an explosion may result. May explode under prolonged exposure to heat. Toxic oxides of nitrogen are produced in fires. Used to make other chemicals and in chemical analysis.
... Intestinal bacteria were involved in the reduction of nitrite ... Absorbed nitrite is rapidly oxidized to nitrate in the blood by a mammalian process ... The process of nitrate generation parallels the methemoglobin (MetHb) formation ... Nitrite oxidation to nitrate may also occur in the stomach prior to absorption, as demonstrated in vitro for mice. However, under in vivo conditions, nitrite is probably absorbed from the stomach before large quantities of nitrate are formed. /Nitrite/
... Nitrite may be further reduced to nitrogen by bacteria under some conditions. In blood, nitrite transforms hemoglobin to methemoglobin and is simultaneously oxidized to nitrate. Normally methemoglobin gradually reverts to hemoglobin through enzymatic reactions. Nitrite has vasodilating properties, probably through transformation into nitric oxide (NO) or a NO-containing molecule acting as a signal factor for smooth muscle relaxation. Nitrite easily transforms into a nitrosating agent in an acidic environment and can react with a variety of compounds, eg ascorbic acid, amines, amides. Nitrosation can also be mediated by bacteria, eg in the stomach. Some reaction products are carcinogenic (eg most nitrosoamines and amides). /Nitrate and nitrite/
No or very slight increase in blood nitrosamine level was found in human subjects after consumption of nitrate-, nitrite-, and/or amine-rich meals /Nitrate, nitrite, and amine/
来源:Hazardous Substances Data Bank (HSDB)
代谢
亚硝酸盐通过与可亚硝化的化合物反应，可能形成亚硝基化合物。许多不同的氨基酸化合物，包括二级胺、三级胺、二级酰胺、三级酰胺、N-取代脲、胍、吲哚（主要是蛋白质中结合的色氨酸）和尿烷，都可以作为可亚硝化的化合物。在胺、酰胺和脲的情况下，形成的亚硝基化合物是N-亚硝胺、N-亚硝酰胺和N-亚硝脲。最常见的亚硝基化合物是那些来自二级胺的。形成的速度通常取决于pH值，并且与未质子化胺的浓度（与胺的碱性成反比）以及N2O3的浓度成正比，因此与NO2浓度的平方成正比。N-亚硝胺形成通常观察到的最佳pH范围是2.5到3.3……弱碱性二级胺（例如吗啡啉、哌嗪、N-甲基苯胺）、N-烷基脲、N-烷基碳酰胺和氨基吡啶的亚硝化反应特别快。强碱性胺，如二甲胺和简单N-烷基酰胺的亚硝化反应相对较慢。三级胺的亚硝化反应，产生二烷基亚硝胺，以及胍的亚硝化反应，产生亚硝氰酰胺和亚硝脲，也相对较慢。在pH 2到5下，亲核阴离子对N-亚硝胺形成的催化作用已被广泛观察到。催化顺序是SCN > I > Br > Cl > 磷酸盐或羧酸盐。SCN-和I-的加速作用引起了人们的广泛关注，因为它们在体内的相关性：吸烟者的唾液SCN-水平相对较高，而I-存在于胃分泌物中。酰胺和相关化合物的亚硝化反应不被亲核阴离子催化。有效抑制亚硝化反应需要能够与亚硝化剂迅速反应并将其转化为无害产物的物质，例如能够还原HNO2或NO，或不可逆地结合NO+基团的化合物。二氧化硫和亚硫酸氢盐、抗坏血酸、生育酚、没食子酸、巯基、几种二羟基苯酚以及一些合成和天然抗氧化剂都是亚硝化反应的抑制剂……已经证明，通过测定尿液中来自前体（高含量的亚硝酸盐和吗啡啉）的内源性N-亚硝基吗啡啉的形成。中国茶抑制了这种N-亚硝化作用，这归因于茶中存在的多酚化合物和抗坏血酸的抑制作用……一项使用抗坏血酸的研究表明，对N-亚硝基脯氨酸形成的抑制并不完全。/亚硝酸盐/
Nitrite may form nitroso compounds by reaction with a nitrosatable compound. Many different amino compounds including secondary and tertiary amines, secondary and tertiary amides, N-substituted ureas, guanidines, indoles (mainly tryptophan-bound in proteins) and urethanes, can act as nitrosatable compounds. In the case of amines, amides and ureas, the formed nitroso compounds are N-nitrosamines, N-nitrosoamides and N-nitrosoureas. The most common nitroso compounds are those derived from secondary amines. The rate of formation is often pH dependent and proportional to the concentration of unprotonated amine (inversely related to the basicity of the amine) and to the concentration of N2O3, and hence to the square of the NO2 concentration. An optimum pH in the range of 2.5 to 3.3 is commonly observed for N-nitrosamine formation ... Nitrosation occurs especially rapidly with weakly basic secondary amines (eg morpholine, piperazine, N-methylaniline), N-alkylureas, N-alkylcarbamates and aminopyrine. Nitrosation occurs relatively slowly with strongly basic amines, such as dimethylamine, and simple N-alkylamides. Nitrosation of tertiary amines, yielding dialkylnitrosamines and nitrosation of guanidines, yielding nitrosocyanamides and nitrosoureas occur relatively slowly. Catalysis of N-nitrosamine formation by nucleophilic anions at pH 2 to 5 has been widely observed. The catalytic order is SCN > I > Br > Cl > phosphate or carboxylate. Acceleration by SCN- and I- have attracted much attention because of their in vivo relevance: salivary SCN- levels are relatively high in smokers and I- is present in gastric secretion. Nitrosation of amides and related compounds is not catalyzed by nucleophilic anions. Effective inhibition of nitrosation requires materials which react readily with and convert the nitrosating agent to innocuous products, e.g.. compounds which either reduce HNO2 or NO or bind the NO+ group irreversibly. Sulfur dioxide and bisulfite ion, ascorbic acid, tocopherols, gallic acid, thiols, several dihydroxy phenols and some synthetic and natural antioxidants are inhibitors of nitrosation ... /It was/ demonstrated the endogenous formation of N-nitrosomorpholine from precursors (high amounts of nitrite and morpholine) by determination in the urine. Chinese tea inhibited this N-nitrosation which was attributed to the inhibitory effect of polyphenolic compounds and ascorbic acid present in tea ... A study with ascorbic acid showing that the inhibition of the formation of N-nitrosoproline was not complete. /Nitrite/
来源:Hazardous Substances Data Bank (HSDB)
代谢
亚硝酸盐及其代谢物通过尿液排出体外。
Nitrites and their metabolites are excreted in the urine. (L1137)
Nitrite causes the autocatalytic oxidation of oxyhemoglobin to hydrogen peroxide and methemoglobin. This elevation of methemoglobin levels is a condition known as methemoglobinemia, and is characterized by tissue hypoxia, as methemoglobin cannot bind oxygen. (A2450, L1613)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
摄入硝酸盐或亚硝酸盐，在导致内源性亚硝化的条件下，可能对人类具有致癌性（2A组）。
Ingested nitrate or nitrite under conditions that result in endogenous nitrosation is probably carcinogenic to humans (Group 2A). (L135)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
健康影响
亚硝酸盐中毒导致高铁血红蛋白血症。亚硝酸盐可能导致怀孕并发症和发育影响。它们也可能具有致癌性。
Nitrite poisoning causes methemoglobinemia. Nitrites may cause pregnancy complications and developmental effects. They may also be carcinogenic. (L1137)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
暴露途径
该物质可以通过吸入其气溶胶和通过吞食被吸收进人体。
The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
Nitrate and nitrite given orally are absorbed and transferred to the blood in the upper part of the gastrointestinal tract. Abundant pectin in the food may delay absorption which may then occur lower down in the intestine, with possible increased risk for microbial transformation of nitrate into nitrite. /Nitrate and nitrite/
Regardless of route of exposure, nitrate and nitrite are rapidly transferred into the blood. Nitrite is gradually oxidized to nitrate which is readily distributed into most body fluids (urine, saliva, gastric juice, sweat, ileostomy fluid). Distribution of nitrate into plasma, erythrocytes, saliva and urine following an oral dose of sodium nitrate has been demonstrated ... Nitrate does not accumulate in the body. /Nitrate and nitrite/
Nitrite rapidly disappeared from a buffered solution at pH<5, simulating gastric conditions, and the rate of disappearance was enhanced by the presence of food ... Nitrite may also react with gastric contents (eg, nitrosation) or be reduced by the GI flora. A large part of nitrite entering the GI tract may thus disappear before absorption takes place ... Absorption of nitrite from the GI tract of rats was slower than that of nitrate. Forty five minutes after intragastric instillation of 13N-labelled nitrite, radioactivity was higher in the stomach and lower in the liver, kidneys, bladder and eviscerated carcass, than in similar experiments with 13N-labelled nitrate ... Nitrite was not absorbed from the caecum and large intestine of rats ... Gastric absorption of nitrite was noted in labelling and gastric emptying studies using rats and mice ... In rats, 63% of nitrite loss from the stomach was due to emptying and 37% to other processes ... Gastric absorption of nitrite seemed faster in mice than in rats. In vivo, the rate of absorption was about 4.5 times greater than the rate of chemical degradation. /Nitrite/
Nitrite is normally absent from the body fluids and tissues of laboratory animals ... The extensive pre-systemic metabolism of nitrite results in an absolute bioavailability (ie the percentage of the dose reaching the systemic circulation) considerably lower than 100%. Intravenous injections and intratracheal instillation of (13)N-labelled nitrite in mice and rabbits resulted in homogenous distribution of radioactivity in the heart, kidneys, liver, stomach, intestines, lungs and bladder (ranging from 4.2 to 10.5%) within 5 minutes. The (13)N was equally distributed in plasma and red blood cells with 15 to 20% of the plasma (13)N bound to proteins ... Thirty minutes after iv injection of nitrite, low levels of nitrite were detected in blood and saliva of dogs ... Nitrite can cross the placenta of rats and guinea-pigs: nitrite injected into pregnant animals appeared after a lag of approximately 20 minutes in fetal blood but at a lower concentration than in maternal blood ... /Nitrite/
Metallkomplexe mit verbrückenden dimethylphosphidoliganden
作者：H. Werner、R. Zolk、W. Hofmann
DOI：10.1016/0022-328x(86)80063-8
日期：1986.3
[(C5H5Co)2(μ-PMe2)2(μ-H)]PF6 (IIa) reacts with PMe3 PMe2H or P(OMe)3 in methanol by opening the hydride bridge and formation of [C5H5(L)Co(μ-PMe2)2Co(H)C5H5]PF6 (L = PMe3 (III); L = PMe2H (IV); L = P(OMe)3 (V)). A solution of the dimethylphosphine complex IV in nitromethane gives a mixture of products from which the compounds trans-[C5H5(PMe2H)Co(μ-PMe2)]2}(PF6)2 (VII) and [(C5H5Co)2(μ-PMe2)3]PF6 (VIII) have been
络合物[（C 5 H ^ 5 Co）的2（μ-PME 2）2（μ-H）] PF 6用Pme（IIA）反应3 PME 2 H或P（OME）3在甲醇中通过打开氢化桥和形成[C的5 ħ 5（L）的Co（μ-PME 2）2的Co（H）C 5 H ^ 5 ] PF 6（L = PME 3（III）为：L = PME 2 H（IV）为：L = P （OMe）3（V））。二甲基膦配合物IV在硝基甲烷中的溶液提供了多种产物的混合物，这些化合物反式- [C 5 H ^ 5（PME 2 2H）钴（μ-PME 2）] 2 }（PF 6）2（VII）和[（C 5 H ^ 5 Co）的2（μ-PME 2）3 ] PF已经分离出6（VIII）。IIa与异氰酸酯CNR（R = Me，Bu t，Ph）的反应过程强烈依赖于溶剂。在硝基甲烷，组合物的产品的顺式-和/或反式- [C 5 H ^ 5（CNR）的Co（μ-PME
Synthesis and Characterization of Zinc(II) Tetraaza Macrocyclic Complexes with Aquo and Nitrate Ligands
The complexes $[Zn(L)(H_2O)_2]\cdot}2NO_2$ (1) and $[Zn(L)(NO_3)_2]$ (2) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo $[14,4,0^1.18},0^7.12}]$docosane) have been synthesized and structurally characterized. The compound 1 crystallizes in the monoclinic system $P2_1/c$ with a = 8.74650(10), b = 18.6880(3), c = $7.96680(10)\AA}$, $\beta}=109.1920(10)^\circ}$, $V=1229.84(3)\AA}^3$, Z = 2. The compound 2 crystallizes in the monoclinic system P1 with a = 8.1292(5), b = 8.9244(5), c = $9.1398(5)\AA}$, $\alpha}=68.035(2)$, $\beta}=70.109(2)$, $\gamma}=75.649(3)^\circ}$, $V=572.70(6)\AA}^3$, Z = 1. The crystal structures of the compounds 1 and 2 show a distorted octahedral coordination geometry around the zinc(II) ion, with four secondary amines and two oxygen atoms of the two water and two nitrate ligands at the axial position. The TGA behaviors of the complexes are significantly affected by the nature of the tetraaza macrocycle and the axial ligands.
Pentamethylcyclopentadienyl-rhodium and -iridium complexes. Part 19. Preparation and reactions of azido-, cyanato-, thiocyanato-, nitrito-, and nitrato-rhodium complexes
作者：William Rigby、Pamela M. Bailey、Jon A. McCleverty、Peter M. Maitlis
DOI：10.1039/dt9790000371
日期：——
bridging ones. Reaction of complex (1) with sodium (or potassium) nitrite gives M[Rh(C5Me5)(NO2)3] which, with PPh3, gives [Rh(C5Me5)(NO2)2(PPh3)]; this complex could also be obtained from [Rh(C5Me5)Cl2(PPh3)] and Ag[NO2]. Reaction of complex (2) with N2O4 gives monomeric [Rh(C5Me5)(NO3)2](24), but reaction of (1) with Ag[NO3] gives the ionic isomer [Rh2(C5Me5)2(NO3)3][NO3](25). Complex (24) gives [Rh(C5Me5)(NO3)2(PPh3)]
[Rh 2（C 5 Me 5）2 Cl 4 ]（1）与NaX的复分解反应得到[Rh 2（C 5 Me 5）2 X 4 ] [X = N 3（2），NCO（9）或SCN（14）]。二聚体叠氮基络合物（2）被不相同的配体[L = PPh 3，P（OR）3，CNR，py等切割]得到单体加合物[Rh（C 5 Me 5）（N 3）2 L ]（3）; 1,10-菲咯啉得到[Rh（C 5 Me 5）（N 3）（phen）] [N 3 ]和2,2'-联吡啶基得到[Rh（C 5 Me 5）（N 3）（bipy）] [Rh（C 5 Me 5）（N 3）3 ]。叠氮基络合物进行羰基化：（2）首先得到[Rh 2（C 5 Me 5）2（NCO）3（N 3）]（含有桥连叠氮化物和桥连氰酸酯配体），然后得到（9），用PPh 3裂解，得到[Rh（C 5 Me 5）（NCO）2（PPh 3）]（12）。配合物（12）也可以通过[Rh（C5
Synthesis, Characterization, and Reactivity of [Ru(bpy)(CH<sub>3</sub>CN)<sub>3</sub>(NO<sub>2</sub>)]PF<sub>6</sub>, a Synthon for [Ru(bpy)(L<sub>3</sub>)NO<sub>2</sub>] Complexes
作者：Daniel A. Freedman、Seth Kruger、Christina Roosa、Chandra Wymer
DOI：10.1021/ic061039t
日期：2006.11.1
fac-[Ru(bpy)(CH3CN)3NO2]PF6 from the known complex [(p-cym)Ru(bpy)Cl]PF6 (p-cym = eta(6)-p-cymene). [(p-cym)Ru(bpy)NO2]PF6 is prepared by reacting [(p-cymene)Ru(bpy)Cl]PF6 with AgNO3/KNO2 or AgNO2. The 15NO2 analogue is prepared using K15NO2. Displacement of p-cymene from [(p-cym)Ru(bpy)NO2]PF6 by acetonitrile gives [Ru(bpy)(CH3CN)3NO2]PF6. The new complexes [(p-cym)Ru(bpy)NO2]PF6 and fac-[Ru(bpy)(CH3CN)3NO2]PF6
Sharing the π-Bonding. An Iron Porphyrin Derivative with Trans, π-Accepting Axial Ligands. Synthesis, EPR and Mössbauer Spectra, and Molecular Structure of Two Forms of the Complex Nitronitrosyl(α,α,α,α-tetrakis(<i>o</i>-pivalamidophenyl)- porphinato)ferrate(II)
作者：Habib Nasri、Mary K. Ellison、Shuxian Chen、Boi Hanh Huynh、W. Robert Scheidt
DOI：10.1021/ja963871a
日期：1997.7.1
The reaction of the iron(II) picketfenceporphyrin derivative [Fe(TpivPP)(NO2)]- (Nasri et al. J. Am. Chem. Soc. 1991, 113, 717) with NO has been examined. The result is a new hexacoordinated iron...
已经研究了铁 (II) 栅栏卟啉衍生物 [Fe(TpivPP)(NO2)]-（Nasri 等人，J. Am. Chem. Soc. 1991, 113, 717）与 NO 的反应。结果是一种新的六配位铁...
