نیل فرنگی

نیل فرنگی (به انگلیسی: Prussian blue) یک ترکیب شیمیایی با شناسه پاب‌کم ۲۷۲۴۲۵۱ است. شکل ظاهری این ترکیب، بلورهای آبی است.

جستارهای وابسته [ویرایش]

ترکیب شیمیایی
نام‌گذاری اتحادیه بین‌المللی شیمی محض و کاربردی
منابع [ویرایش]

«IUPAC GOLD BOOK». بازبینی‌شده در ۱۸ مارس ۲۰۱۲.
این یک نوشتار خُرد پیرامون شیمی است. با گسترش آن به ویکی‌پدیا کمک کنید.
رده‌های صفحه: Articles with changed EBI identifierChemboxes which contain changes to verified fieldsترکیب‌های آهنترکیب‌های هماهنگ‌کننده داروهای ضروری سازمان بهداشت جهانی رنگدانه‌های معدنی سیانورهامواد شیمیایی در عکاسی

قس عربی

أزرق بروسی
الاسم النظامی Iron(II,III) hexacyanoferrate(II,III)
أسماء أخرى Berlin blue
Ferric ferrocyanide
Ferric hexacyanoferrate
Iron(III) ferrocyanide
Iron(III) hexacyanoferrate(II)
Parisian blue

معلومات عامة
رقم الکاس 14038-43-8
بوب کیم 2724251
رقم إی سی 237-875-5
ChEBI 30069
RTECS number V03AB31
م إ ن م ج [Fe+3].[Fe+3].[Fe+3].[Fe+3].N#C[Fe-4](C#N)(C#N)(C#N)(C#N)C#N.N#C[Fe-4](C#N)(C#N)(C#N)(C#N)C#N.N#C[Fe-4](C#N)(C#N)(C#N)(C#N)C#N
م ک د
[وسع]

خصائص
صیغة کیمیائیة C18Fe7N18
کتلة مولیة 859.23 غ.مول−1
المظهر Blue opaque crystals
علم الصیدلة
Routes of
administration Oral
مخاطر
صحیفة بیانات سلامة المادة MSDS prussian blue
مرکبات قریبة
کتیونات أخرى Potassium ferrocyanide
Sodium ferrocyanide

فی حال عدم ذکر الشروط فإن
البیانات الواردة أعلاه مقاسة فی الشروط النظامیة

ومدونة حسب النظام الدولی للوحدات

الأزرق البروسی خضاب أزرق غامق صیغته الکیمیائیة Fe7(CN)18⋅14H2O. ولهذا الخضاب أسماء أخرى هی أزرق برلین وفی الرسم الأزرق الفارسی.


موجة الکاناجاوا العظیمة، یظهر فی هذه اللوحة الاستخدام المکثف للأزرق البروسی
.

[أخف] ع · ن · تدرجات الأزرق
Air Force blue Alice blue Azure Baby blue أزرق Brandeis blue Carolina blue Cerulean أزرق کوبلت أزرق کولومبیا

Cornflower blue Dark blue Denim Dodger blue Duke blue أزرق مصری Electric blue Han blue نیلی (لون) Intl. Klein blue

Light blue Majorelle blue أزرق مایا أزرق منتصف اللیل أزرق بحری Periwinkle أزرق فارسی Powder blue أزرق بروسی أزرق ملکی

زافیر سماوی أزرق فولاذی أزرق لازوردی Yale blue

العینات الظاهرة أعلاه هی تمثیلة فقط.
هذه المقالة بذرة تحتاج للنمو والتحسین؛ فساهم فی إثرائها بالمشارکة فی تحریرها.
تصنیفات: صفحات کیمیاء تحتاج إلى رسوم بنىقوالبأدویة أساسیة حسب منظمة الصحة العالمیةدرجات الأزرقمرکبات حدیدخضاب لاعضویمرکبات تساندیة

قس انگلیسی
Prussian blue is a dark blue pigment with the idealized formula Fe7(CN)18. Another name for the color Prussian blue is Berlin blue or, in painting, Parisian blue. Turnbull's blue is the same substance but is made from different reagents.
Prussian blue was one of the first synthetic pigments. It is employed as a very fine colloidal dispersion, as the compound itself is not soluble in water. It is famously complex,[1] owing to the presence of variable amounts of other ions and the sensitive dependence of its appearance on the size of the colloidal particles formed when it is made. The pigment is used in paints, and it is the traditional "blue" in blueprints.
In medicine, Prussian blue is used as an antidote for certain kinds of heavy metal poisoning (caesium and thallium).
Prussian blue lent its name to prussic acid, which was derived from it, and to ferrocyanide (originally meaning "blue compound of iron", from Latin ferrum and Greek κυανεος). As ferrocyanide is made of iron and CN ligands, reinterpreting the component "-cyanide" in the compound word produced the word "cyanide" for compounds containing the CN radical.
Contents [hide]
1 History
2 Production
2.1 "Turnbull's blue"
3 Properties
3.1 Crystal structure
3.2 Color
4 Uses
4.1 Pigment
4.2 Medicine
4.3 Laboratory histopathology stain for iron
4.4 By machinists and toolmakers
4.5 Analytical chemistry
5 Safety
6 See also
7 References
8 External links
[edit]History

Prussian blue [Fe4[Fe(CN)6]3] was probably synthesized for the first time by the paint maker Diesbach in Berlin around the year 1706.[2] Most historical sources do not mention a first name of Diesbach. Only Berger refers to him as Johann Jacob Diesbach.[3] It was named "Preußisch blau" and "Berlinisch Blau" in 1709 by its first trader.[4] The pigment replaced the expensive Lapis lazuli and was an important topic in the letters exchanged between Johann Leonhard Frisch[5] and the president of the Royal Academy of Sciences, Gottfried Wilhelm Leibniz, between 1708 and 1716.[4] It is first mentioned in a letter written by Frisch to Leibniz, from March 31, 1708. Not later than 1708, Frisch began to promote and sell the pigment across Europe. By August 1709, the pigment had been termed "Preussisch blau"; by November 1709, the German name "Berlinisch Blau" had been used for the first time by Frisch. Frisch himself is the author of the first known publication of Prussian blue in the paper Notitia Coerulei Berolinensis nuper inventi in 1710, as can be deduced from his letters. Diesbach had been working for Frisch since about 1701.
In 1731, Georg Ernst Stahl published an account of the first synthesis of Prussian blue.[6] The story involves not only Diesbach but also Johann Konrad Dippel. Diesbach was attempting to create a red lake pigment from cochineal but obtained the blue instead as a result of the contaminated potash he was using. He borrowed the potash from Dippel, who had used it to produce his "animal oil". No other known historical source mentions Dippel in this context. It is therefore difficult to judge the reliability of this story today. In 1724, the recipe was finally published by John Woodward.[7][8][9]
To date, the "Entombment of Christ", dated 1709 by Pieter van der Werff (Picture Gallery, Sanssouci, Potsdam) is the oldest known painting where Prussian blue was used. Around 1710, painters at the Prussian court were already using the pigment. At around the same time, Prussian blue arrived in Paris, where Antoine Watteau and later his successors Nicolas Lancret and Jean-Baptiste Pater used it in their paintings.[10]


"The Great Wave off Kanagawa" by Hokusai, a famous artwork which makes extensive use of Prussian blue.
This Prussian blue pigment is significant since it was the first stable and relatively lightfast blue pigment to be widely used following the loss of knowledge regarding the synthesis of Egyptian Blue. European painters had previously used a number of pigments such as indigo dye, smalt, and Tyrian purple, which tend to fade, and the extremely expensive ultramarine made from lapis lazuli. Japanese painters and woodblock print artists likewise did not have access to a long-lasting blue pigment until they began to import Prussian blue from Europe.
In 1752 the French chemist Pierre J. Macquer made the important step of showing the Prussian blue could be reduced to a salt of iron and a new acid, which could be used to reconstitute the dye.[11] The new acid, hydrogen cyanide, first isolated from Prussian blue in pure form and characterized about 1783 by the Swedish chemist Carl Wilhelm Scheele, was eventually given the name Blausäure (literally "Blue acid") because of its derivation from Prussian blue, and in English became known popularly as Prussic acid. Prussian blue would also give the name to the ferrocyanide and cyanide family of compounds. Ferrocyanide (which is yellow) was coined as Neo Latin for "iron-containing blue material", since it was first isolated from Prussian blue. Cyanide, a colorless anion that forms in the process of making Prussian Blue, was named, in turn, for hydrogen cyanide (also colorless), and ultimately from ferrocyanide. It is for this reason that cyanide, even though the name of a colorless radical, is a Latinized form of the Greek word for "dark blue."
[edit]Production

Prussian blue is produced by oxidation of ferrous ferrocyanide salts. These white solids have the formula M2Fe[Fe(CN)6] where M+ = Na+ or K+. The iron in this material is all ferrous, hence the absence of deep color associated with the mixed valency. Oxidation of this white solid with hydrogen peroxide or sodium chlorate produces ferricyanide and affords Prussian Blue.[12]
A "soluble" form of PB, K[FeIIIFeII(CN)6], which is really colloidal, can be made from potassium ferrocyanide and iron(III):
K+ + Fe3+ + [FeII(CN)6]4- → KFeIII[FeII(CN)6]
The similar reaction of potassium ferricyanide and iron(II) results in the same colloidal solution, because [FeIII(CN)6]3- is converted into ferrocyanide.
"Insoluble" Prussian blue is produced if in the reactions above an excess of Fe3+ or Fe2+, respectively, is added. In the first case:
4Fe3+ + 3[FeII(CN)6]4- → FeIII[FeIIIFeII(CN)6]3 [13]
[edit]"Turnbull's blue"


Ferricyanide ion, used to make 'Turnbull's blue'.
In former times, it was thought that addition of Fe(II) salts to a solution of ferricyanide affords a material different from Prussian blue. The product was traditionally named "Turnbull's Blue" (TB). It has been shown, however, by means of X-ray diffraction and electron diffraction methods, that the structures of PB and TB are identical.[14][15] The differences in the colors for TB and PB reflect subtle differences in the method of precipitation, which strongly affects particle size and impurity content.
[edit]Properties

Prussian blue is a microcrystalline blue powder. It is insoluble, but the crystallites tend to form a colloid. Such colloids can pass through fine filters.[1] Despite being one of the oldest known synthetic compounds, the composition of Prussian blue remained uncertain for many years. The precise identification of Prussian blue was complicated by three factors:
Prussian blue is extremely insoluble but also tends to form colloids;
Traditional syntheses tend to afford impure compositions;
Even pure Prussian blue is structurally complex, defying routine crystallographic analysis.
[edit]Crystal structure
The chemical formula of insoluble Prussian blue is Fe7(CN)18·xH2O, where x = 14–16. The structure was determined by using IR spectroscopy, Moessbauer spectroscopy, X-ray crystallography, and neutron crystallography. Since X-ray diffraction cannot distinguish carbon from nitrogen, the location of these lighter elements is deduced by spectroscopic means as well as by observing the distances from the iron atom centers.
PB has a cubic lattice structure. Soluble PB crystals contain interstitial K+ ions; insoluble PB has interstitial water instead.
In ideal insoluble PB crystals, the cubic framework is built from Fe(II)-C-N-Fe(III) sequences, with Fe(II)-carbon distances of 1.92 Å and Fe(III)-nitrogen distances of 2.03 Å. One-fourth of the sites of Fe(CN)6 subunits are vacant (empty), leaving three such groups. The empty nitrogen sites are filled with water molecules instead, which are coordinated to Fe(III).
The Fe(II) centers, which are low spin, are surrounded by six carbon ligands in an octahedral configuration. The Fe(III) centers, which are high spin, are octahedrally surrounded on average by 4.5 nitrogen atoms and 1.5 oxygen atoms (the oxygen from the six coordinated water molecules). Additional eight (interstitial) water molecules are present in the unit cell, either as isolated molecules or hydrogen bonded to the coordinated water.
The composition is notoriously variable due to the presence of lattice defects, allowing it to be hydrated to various degrees as water molecules are incorporated into the structure to occupy cation vacancies. The variability of Prussian blue's composition is attributable to its low solubility, which leads to its rapid precipitation without the time to achieve full equilibrium between solid and liquid.[16] [17]
[edit]Color
Prussian blue is strongly colored and tends towards black and dark blue when mixed into oil paints. The exact hue depends on the method of preparation, which dictates the particle size. The intense blue color of Prussian blue is associated with the energy of the transfer of electrons from Fe(II) to Fe(III). Many such mixed-valence compounds absorb certain wavelengths of visible light resulting from intervalence charge transfer. In this case, orange-red light around 680 nanometers in wavelength is absorbed, and the reflected light appears blue as a result.
Like most high chroma pigments, Prussian blue cannot be accurately displayed on a computer display.
PB is electrochromic—changing from blue to colorless upon reduction. This change is caused by reduction of the Fe(III) to Fe(II) eliminating the intervalence charge transfer that causes Prussian blue's color.
[edit]Uses

[edit]Pigment
Because it is easily made, cheap, non-toxic, and intensely colored, Prussian blue has attracted many applications. The dominant uses are for pigments: approximately 12,000 tonnes of Prussian blue are produced annually for use in black and bluish inks. A variety of other pigments also contain the material.[12] Engineer's blue and the pigment formed on cyanotypes—giving them their common name blueprints. Certain crayons were once colored with Prussian blue (later relabeled Midnight Blue). It is also a popular pigment in paints. Similarly, Prussian blue is the basis for laundry bluing.
[edit]Medicine
Prussian blue's ability to incorporate monocations makes it useful as a sequestering agent for certain heavy metal poisons. Pharmaceutical-grade Prussian blue in particular is used for patients who have ingested thallium or radioactive caesium. According to the International Atomic Energy Agency, an adult male can eat at least 10 grams of Prussian blue per day without serious harm. The U.S. Food and Drug Administration (FDA) has determined that the "500 mg Prussian blue capsules, when manufactured under the conditions of an approved New Drug Application (NDA), can be found safe and effective therapy" in certain poisoning cases.[18] Radiogardase (Prussian blue in soluble capsules [19]) is a commercial product for the removal of caesium-137 from the intestine and so indirectly from the bloodstream by intervening in the enterohepatic circulation of caesium-137,[20] reducing the internal residency time (and exposure) by about two-thirds.
[edit]Laboratory histopathology stain for iron


Prussian blue stain
Prussian blue is a common histopathology stain used by pathologists to detect the presence of iron in biopsy specimens, such as in bone marrow samples. The original stain formula, known historically (1867) as "Perls' Prussian blue" after its inventor, German pathologist Max Perls (1843–1881), used separate solutions of potassium ferrocyanide and acid to stain tissue (these are now used combined, just before staining). Iron deposits in tissue then form the purple Prussian blue dye in place, and are visualized as blue or purple deposits.[21] The formula is also known as Perls Prussian blue and (incorrectly) as Perl's Prussian blue.
[edit]By machinists and toolmakers
Prussian blue in oil paint is the traditional material used for spotting metal surfaces such as surface plates and bearings for hand scraping. A thin layer of non-drying paste is applied to a reference surface and transfers to the high spots of the workpiece. The toolmaker then scrapes, stones, or otherwise removes the marked high spots. Prussian blue is preferable because it will not abrade the extremely precise reference surfaces as many ground pigments may.
[edit]Analytical chemistry
Prussian blue is formed in the Prussian blue assay for total phenols. Samples and phenolic standards are given acidic ferric chloride and ferricyanide which is reduced to ferrocyanide by the phenols. The ferric chloride and ferrocyanide react to form Prussian blue. Comparing the absorbance at 700 nm of the samples to the standards allows for the determination of total phenols.[22]
[edit]Safety

Despite the fact that it is prepared from cyanide salts, Prussian blue is nontoxic because the cyanide groups are tightly bound to Fe. Other polymeric cyanometalates are similarly stable with low toxicity.[citation needed]
[edit]See also

Egyptian Blue
Fluorescein
Gentian violet
Han Purple
Midnight blue
Potassium ferrocyanide
Potassium ferricyanide
[edit]References

^ a b Dunbar, K. R. and Heintz, R. A. (1997). "Chemistry of Transition Metal Cyanide Compounds: Modern Perspectives". Progress in Inorganic Chemistry 45: 283–391.
^ Jens Bartoll. "The early use of prussian blue in paintings" (PDF). 9th International Conference on NDT of Art, Jerusalem Israel, 25–30 May 2008. Retrieved 2010-01-22.
^ J. E. Berger: Kerrn aller Fridrichs=Städtschen Begebenheiten Manuskript, Berlin, ca.1730 (Berlin, Staatsbibliothek zu Berlin – Preußischer Kulturbesitz, Handschriftenabteilung, Ms. Boruss. quart. 124)
^ a b J. L. Frisch: Briefwechsel mit Gottfried Wilhelm Leibniz L. H. Fischer (ed.), Berlin, Stankiewicz Buchdruck, 1896, reprint Hildesheim/New York: Georg Olms Verlag, 1976
^ There is a Wikipedia article in German
^ G. E. Stahl: Experimenta, Observationes, Animadversiones CCC Numero, Chymicae et Physicae, (Berlin, 1731), pp. 281–283.
^ Woodward, J. (1724–1725). "Praeparatio coerulei Prussiaci es Germanica missa ad Johannem Woodward.. [Preparation of Prussian blue sent from Germany to John Woodward...]". Philosophical Transactions of the Royal Society of London 33 (381): 15–17. DOI:10.1098/rstl.1724.0005.
^ Brown, John (1724–1725). "Observations and Experiments upon the Foregoing Preparation". Philosophical Transactions 33 (381): 17–24. Bibcode 1724RSPT...33...17B. DOI:10.1098/rstl.1724.0006. JSTOR 103734.. The recipe was subsequently published in [Étienne-François] Geoffroy, "Observations sur la Preparation de Bleu de Prusse ou Bleu de Berlin," Mémoires de l'Académie royale des Sciences année 1725 (Paris, 1727), pp. 153–172.
^ Sarah Lowengard, The Creation of Color in Eighteenth-Century Europe (New York, New York: Columbia University Press, 2008), Chapter 23: Prussian Blue.
^ J.Bartoll, B. Jackisch, M. Most, E. Wenders de Calisse, C. M. Vogtherr: Early Prussian Blue. Blue and green pigments in the paintings by Watteau, Lancret and Pater in the collection of Frederick II of Prussia In: TECHNE 25, 2007, pp. 39–46
^ Pierre-Joseph Macquer (1752) "Éxamen chymique de bleu de Prusse," Mémoires de l'Académie royale des Sciences année 1752 . . . (Paris, 1756), pp. 60–77. This article was reviewed in "Sur le bleu de Prusse," Histoire de l'Académie royale des Sciences... (1752), (Paris, 1756), pp. 79–85.
^ a b Völz, Hans G. et al. "Pigments, Inorganic" in Ullmann's Encyclopedia of Industrial Chemistry, 2006 Wiley-VCH, Weinheim. doi:10.1002/14356007.a20_243.pub2.
^ Egon Wiberg,Nils Wiberg,Arnold Frederick Holleman: Inorganic chemistry, p.1444. Academic Press, 2001; Google books
^ Ozeki, Toru.; Matsumoto, Koichi.; Hikime, Seiichiro. (1984). "Photoacoustic spectra of prussian blue and photochemical reaction of ferric ferricyanide". Analytical Chemistry 56 (14): 2819. DOI:10.1021/ac00278a041.
^ Izatt, Reed M.; Watt, Gerald D.; Bartholomew, Calvin H.; Christensen, James J. (1970). "Calorimetric study of Prussian blue and Turnbull's blue formation". Inorganic Chemistry 9 (9): 2019. DOI:10.1021/ic50091a012.
^ Herren, F.; Fischer, P.; Ludi, A.; Haelg, W. (1980). "Neutron diffraction study of Prussian Blue, Fe4[Fe(CN)6]3.xH2O. Location of water molecules and long-range magnetic order". Inorganic Chemistry 19 (4): 956. DOI:10.1021/ic50206a032.
^ Lundgren, C. A.; Murray, Royce W. (1988). "Observations on the composition of Prussian blue films and their electrochemistry". Inorganic Chemistry 27 (5): 933. DOI:10.1021/ic00278a036.
^ "Questions and Answers on Prussian Blue". Retrieved 2009-06-06.
^ Radiogardase: Package insert with formula
^ Heyltex Corporation – Toxicology
^ Formula for Perls' Prussian blue stain. Accessed April 2, 2009.
^ Tannin ChemistryPDF (1.41 MB)Accessed December 19, 2009
[edit]External links

The FDA's page on prussian blue
The CDC's page on prussian blue
National Pollutant Inventory – Cyanide compounds fact sheet
Heyltex Corporation distributors of Radiogardase (Prussian blue insoluble capsules)
Sarah Lowengard, "Prussian Blue" in The Creation of Color in Eighteenth Century Europe Columbia University Press, 2006
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Categories: Shades of blueCyanidesIron compoundsInorganic pigmentsCoordination compoundsMixed valence compoundsPhotographic chemicalsWorld Health Organization essential medicines
قس عبری

כחול פּרוּסי (באנגלית: Prussian blue) הוא פיגמנט בלתי מסיס המשמש לייצור צבעים ובעבר שימש לייצור דיו. כחול פרוסי התגלה במקרה על ידי היינריך דיסבאך בשנת 1704 בברלין כשניסה לייצר צבע אדום. החומר נקרא לכן גם "כחול ברלין". שמות אחרים קשורים להרכב הכימי: ברזל פרוציאניד (iron(III) ferrocyanide) או ברזל הקסה-ציאנופראט (iron(III) hexacyanoferrate)
תוכן עניינים [הצגה]
[עריכה]כימיה ותכונות החומר

כחול פרוסי הוא תרכובת של ציאניד וברזל
מספר מולקולות המים x הוא בין 14 ל-16.
צפיפות: 1.9 גרם לסמ"ק[1]
טמפרטורת התכה: אין, מתפרק מעל 140 מעלות צלזיוס
CAS: 14038-43-8
ההרכב המדויק והמבנה של כחול פרוסי לא היו ידועים במשך תקופה ארוכה, משום שהחומר אינו מסיס ונוטה לייצור קולואידים במים, המבנה מסובך ואינו ניתן לגילוי באמצעות עקיפת קרני X רגילה (משום שאי אפשר להבחין בעקיפת קרני X בין פחמן לחנקן) והסטויכיומטריה אינה ברורה משום שקשה להפיקו בצורה טהורה.
כיום ידוע כי הציאניד משמש כליגנד מגשר: אטום החנקן נקשר לקטיון של ברזל תלת ערכי והפחמן - לברזל דו ערכי (Fe(II)-CN-Fe(III; כל אטומי הברזל בקואורדינציה 6, כלומר קשורים לשישה בסיסי לואיס: יון ציאניד או מולקולת מים (כל אטום ברזל במרכז אוקטאדר). המרחק בין אטום ברזל דו ערכי לאטום פחמן הוא 1.92Å והמרחק בין אטום ברזל תלת ערכי לאטום החנקן הוא 2.03Å. המבנה הגבישי הוא רשת של אטומי ברזל דו ערכי ותלת ערכי לסירוגין, מקושרים באמצעות אניוני ציאניד. כיוון שיש שלושה אטומי ברזל דו ערכי לכל ארבעה אטומי ברזל תלת ערכי, הרי שרבע מהמקומות של ברזל דו ערכי בסריג הגבישי מוחלפים במולקולות מים, מים מחליפים גם ציאניד כליגנדים מגשרים[2]. מולקולות המים נוספות נמצאות בין יחידות המבנה. כחול פרוסי מופק מתגובה של ברזל כלורי FeCl3 עם אשלגן פרוציאניד . לקבלת דיו מסננים ומרחיפים את התוצר בחומצה אוקסאלית מהולה מחוממת.
הצבע החזק נובע מהעברת מטען מברזל דו ערכי לברזל תלת ערכי בבליעת פוטון. מקסימום הבליעה באורך גל 680nm והאור המועבר או המוחזר נראה, לכן, כחול (צבע משלים).
כחול פרוסי משנה צבעו מכחול לבן בהפעלת מתח חשמלי (אפקט אלקטרוכרומי[3]) התופעה נגרמת מחמצון ברזל דו ערכי לברזל תלת ערכי.
בהארה באור נראה עובר הברזל ממצב של ספין נמוך (אלקטרונים מזווגים ברמת d) לספין גבוה (סידור אלקטרונים באורביטלי d שונים בספינים מקבילים). זהו אחד החומרים הבודדים שידועה בהם תגובה מגנטית לאור.
[עריכה]שימושים

כחול לכביסה: אריגים לבנים מקבלים עם השימוש גוון אפרפר או צהבהב (בז'), הוספת מעט צבע כחול לאריג גורמת לו להראות לבן יותר.
התאמת משטחים: הפיגמנט מורחף בשמן וצובע את משטח הייחוס, מחככים את החלק המעובד במשטח והאזור שנצבע (על ידי העברת צבע ממשטח הייחוס) הוא הנקודה הבולטת. כך ניתן לבחון מישוריות (flatness) של עצמים.
הדפסת מונוכרום בצבע כחול (העתקת שמש).
יכולתו של הכחול הפרוסי לקשור קטיונים חד ערכיים מנוצלת לטיפול במי שבלעו צזיום או תליום רדיואקטיביים. לפי הסוכנות הבינלאומית לאנרגיה אטומית, אדם מבוגר יכול לאכול 10 גרם מהחומר ללא נזק.
[עריכה]הכחשת שואה

גרמר רודולף (Germar Rudolf), מכחיש שואה גרמני (כימאי בהשכלתו), טוען כי היעדר כחול פרוסי מקירות תאי הגזים בטרבלינקה והימצאות החומר על קירות מבנים שבהם השתמשו במימן ציאנידי לצורכי חיטוי מוכיחים כי הקירות לא נחשפו לציאניד, כלומר שלא התבצעה השמדה בגז במבנים אלו[4].
ריצ'רד גרין, כימאי שיצא כנגד גרמר רודולף, הסביר כי כדי ליצור כחול פרוסי ממימן ציאנידי הנספח לקיר, על הטיח להיות לח ובסיסי (בתנאים חומציים או נייטרליים המימן הציאנידי לא יתפרק ולא ישחרר את אניון הציאניד שיוכל להיקשר לקטיוני ברזל). כחול פרוסי נוצר, לכן, על קירות חדר החיטוי שהטיח בו היה על בסיס סיד (lime) ולא על קירות חדרי הגזים שהיו עשויים בטון.
הצמד המוזיקלי פראשן בלו (כחול פרוסי באנגלית) ידוע בתכנים הגזעניים של שיריו.
[עריכה]קישורים חיצוניים

ההיסטוריה של הצבע כחול פרוסי
ההיסטוריה של כחול פרוסי ושל ציאניד
אודות כחול פרוסי
אודות השימוש הראשון בכחול הפרוסי
[עריכה]הערות שוליים

^ Eisen(III)-hexacyanoferrat(II) - PHYSIKALISCH-CHEMISCHE EIGENSCHAFTEN
^ המבנה הגבישי הוצע על ידי H. J. Buser ופורסם ב Inorganic Chemistry Vol. 11, p 2704 1977
^ http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=4,773,741.PN.&OS=PN/4,773,741&RS=PN/4,773,741
^ Dipl.-Chem. Germar Rudolf, Some considerations about the "Gas Chambers" of Auschwitz and Birkenau, Paper presented at the 1st Australian Revisionist Conference, August 9, 1998
קטגוריות: תרכובות אי-אורגניותפיגמנטים
משובים קודמיםמשוב על הערך

قس ایتالیئی
Il blu di Prussia (In tedesco Preußisch Blau, noto anche come Blu di Berlino) è un pigmento blu scuro usato nelle vernici e un tempo nei disegni tecnici. Venne scoperto casualmente a Berlino nel 1704 da Diesbach e Dippel.
Ha diversi nomi chimici, tra cui: ferrocianuro ferrico, ferricianuro ferroso, esacianoferrato(II) di ferro(III), esacianoferrato(III) di ferro(II), e esacianoferrato ferrico. Il blu di Prussia è un colore intenso e tende verso il nero o il viola scuro quando viene mischiato con altri colori ad olio.
Il blu di Prussia è stato descritto con 2 forme, la "soluble" , KFe(III)[Fe(II)(CN)6] e la forma insolubile, Fe(III)4[Fe(II)(CN)6]3·6H2O, il nome deriva da motivazioni storiche più che da connotazioni di solubilità. Keggin e Miles hanno suggerito una struttura cubica a facce centrate nel quale il ferro ad alto spin e il ferrocianuro a basso spin si dispongono in una struttura ottaedrica legati a -NC e -CN unità, rispettivamente con K+ controione sito interstiziale. La forma insolubile descritta da Ludi et al. manca di un quarto di ioni esacianoferrato con il sito dell'azoto occupato invece da un cluster di molecole d'acqua coordinate al sito del Fe(III) con altre molecole d'acqua interstiziali.
Si ottiene per reazione tra il ferrocianuro di potassio e ioni di ferro(III); il colore è talmente intenso e caratteristico da rendere questa reazione adatta per il rilevamento del ferro o dei cianuri.
Il blu di Prussia può essere utilizzato anche da agente chelante e nel trattamento per l'avvelenamento da metalli pesanti. In particolare, viene usato per i pazienti che hanno ingerito cesio o tallio radioattivi (o anche per il tallio non-radioattivo).
Il blu intenso del blu di Prussia è causato dal trasferimento di elettroni da un atomo di ferro ad un altro all'interno della molecola. Viene assorbita luce a 680 nm (rosso), provocando il trasferimento di un elettrone da un atomo di Fe(II) a uno vicino di Fe(III). La luce trasmessa risulta blu.
Nonostante la presenza dello ione di cianuro, il blu di Prussia, come altri ferrocianuri, non è particolarmente tossico a causa del forte legame tra gli ioni di cianuro e di ferro. Comunque, se trattato con acidi forti concentrati può liberare il cianuro in forma di cianuro di idrogeno (più noto come acido cianidrico), che è estremamente tossico.
Indice [mostra]
Impieghi [modifica]

Sospeso come colloide in acqua, il blu di Prussia è la base della tintura in blu dei tessuti.
Come "blu degli ingegneri" viene miscelato con un materiale oleoso, e strofinato su una superficie metallica. Questa viene a sua volta strofinata con un'altra superficie, di riscontro, e la rimozione del pigmento indica la posizione dei punti in rilievo. Quindi può essere usato per indicare la regolarità di una superficie o di un supporto.
Joseph Whitworth rese popolare il primo metodo pratico per preparare accuratamente delle superfici piatte negli anni 1830, usando il blu di Prussia e delle tecniche di raschiamento su tre superfici di prova. Fino alla sua introduzione delle tecniche di raschiamento, lo stesso metodo con tre superfici veniva usato con delle tecniche di lucidatura, che davano però risultati meno accurati. Ciò portò ad una esplosione dello sviluppo di strumenti di precisione che usavano queste tecniche per generare superfici piatte come base per l'ulteriore costruzione di forme precise.
Il blu di Prussia può essere miscelato con alcoli metilati per creare una macchia ad essiccazione rapida. Queste macchie vengono usate per le operazioni di marcatura nella lavorazione dei metalli, per trasferire lo schema di lavorazione sul pezzo prima che venga lavorato.
Voci correlate [modifica]

ferrocianuro di potassio
ferricianuro di potassio
Altri progetti [modifica]

Wikibooks contiene un modulo sull'analisi del ferro col blu di Prussia
Collegamenti esterni [modifica]

(EN) Il blu di Prussia come medicamento
(EN) Pagina web dell'FDA sul blu di Prussia
[nascondi] V · D · MGradazioni di blu
Carta da zucchero Blu alice Acquamarina Ciano Blu polvere Blu chiaro Pervinca Celeste Blu fiordaliso Blu scuro

Lavanda Blu Dodger Azzurro Blu acciaio Ceruleo Blu Savoia Denim Blu ceruleo Blu reale Cobalto

Blu Blu di Persia Blu pavone Int. Klein Blue Blu notte Indaco Blu di Prussia Blu oltremare Blu marino Zaffiro

Denim chiaro Blu Bondi Acqua Fiordaliso Blu cadetto Blu reale Blu elettrico

Portale Pittura: accedi alle voci di Wikipedia che trattano di pittura
Categorie: Pigmenti inorganiciTintura

قس فرانسه
Le Bleu de Prusse (Preußischblau ou Berliner Blau en allemand), aussi connu sous le nom de Bleu de Berlin en raison de sa ville de découverte, est un pigment bleu foncé utilisé en peinture. Il fut découvert accidentellement2 par le peintre Heinrich Diesbach à Berlin en 1704 ou 1705.
Sa formule chimique est Fe7(CN)18(H2O)x, où x varie de 14 à 18. C'est un ferrocyanure ferrique.
Il donne une coloration violette quand on le dissout dans du tartrate d'ammonium.
Sommaire [masquer]
1 Préparation
2 Utilisations
2.1 Peinture
2.2 Autres utilisations
3 Notes et références
Préparation[modifier]

Procédé utilisé par John Woodward en 1724 :
On mélange en solution dans l'eau six parts de sulfate ferreux et six parts de ferrocyanure de potassium, on y ajoute vingt-quatre parts d'acide chlorhydrique et une part d'acide sulfurique. Au bout de plusieurs heures on verse dans la préparation du chlorure de chaux. Le Bleu de Prusse précipite au fond du récipient. Il ne reste qu'à le purifier du ferricyanure de potassium qu'il contient en faisant précipiter ce dernier par l'action d'un peu de chlorure ferrique dilué. Le Bleu de Prusse peut être alors séché.
Utilisations[modifier]

Peinture[modifier]


Un Bleu de Prusse
Le Bleu de Prusse est identifié dans le Colour Index sous le code PB27. Il s'agit d'un pigment semi-transparent, très colorant donc à utiliser avec parcimonie.
Il est aujourd'hui délaissé au profit du bleu phtalo ou du bleu d'indanthrène.
Parmi ses noms commerciaux, utilisés dans les couleurs pour artistes, on trouve le Bleu Intense, le Bleu Berlin, le Bleu de Paris.
Autres utilisations[modifier]
Le Bleu de Prusse est aussi utilisé
pour traiter les intoxications et les contaminations au thallium et au césium ;
pour vérifier l'ajustement de différents engrenages en mécanique automobile ;
comme couche de marquage en chaudronnerie car il résiste à l'eau et aux solvants.
Notes et références[modifier]

↑ Masse molaire calculée d’après Atomic weights of the elements 2007 [archive] sur www.chem.qmul.ac.uk.
↑ (en) La création accidentelle du Bleu de Prusse [archive]
[masquer] v · d · m Teintes de bleu
Acier

Aigue-marine

Azur

Azur clair

Azurin

Barbeau

Bleu

Bleuet

Bondi

Cæruléum

Canard

Céleste

Charrette

Ciel

Cobalt

Cyan

Denim

Dragée

Égyptien

Électrique

France (de)

Fumée

Givré

Gris de lin

Horizon

Indigo

Klein

Lavande

Majorelle

Marine

Maya

Mers du sud (des)

Minéral

Minuit (de)

Nuit

Outremer

Paon

Pastel

Persan

Pervenche

Pétrole

Prusse (de)

Safre

Saphir

Sarcelle

Smalt

Tiffany

Turquin

Turquoise

Portail de la chimie Portail des couleurs
Catégories : Composé du ferBleuCyanureTest chimiquePigmentPigment minéralPigment synthétique