pyridine-2-acetamide oxime

What I am asking about is the chemical structure of diborane ($B_2H_6 $). This diborane is one of the borohydride compounds, and its structure is particularly delicate.
The structure of diborane contains diboron atoms and hexahydride atoms. The valence electron configuration of boron atoms is $2s ^ {2} 2p ^ {1} $, which is usually trivalent in compounds. In diborane, diboron atoms are connected by dihydrogen atoms in a special bridge bond, which is also known as a three-center two-electron bond.
Specifically, two boron atoms each form bonds with other atoms in $sp ^ {3} $hybrid orbitals. Among them, the boron atom forms a normal $\ sigma $bond with two hydrogen atoms, and the tetrahydrogen atom is in the same plane. The other dihydrogen atom is located above and below this plane, and is connected to the two boron atoms by a bridge bond. The formation of this bridge bond originates from the fact that the number of valence orbitals of boron atoms is more than the number of valence electrons, and it has the characteristic of missing electrons. The electron cloud of this three-center two-electron bond is distributed in the triangular region composed of three atoms, maintaining the bond between boron and hydrogen atoms. The unique structure of
diborane makes it chemically active. Because of its lack of electron bridge bonds, it is easy to react with molecules with solitary pairs of electrons. It is common in many fields such as organic synthesis and is used as a reducing agent and a hydrogenating agent. This unique structure and active properties play an important role in both chemical research and industrial applications, making it an interesting and crucial research object in the field of chemistry.

The genus of realgar stone, its main users have the following ends:
First, it is used for healing diseases. In ancient medicine, realgar is warm and delicious, and has the effect of detoxifying and killing insects, dryness and dampness to remove phlegm, and malaria. It is often used to treat carbuncle swelling and boils, snake and insect bites, abdominal pain accumulated by insects, convulsions, malaria and other diseases. As stated in the Compendium of Materia Medica, realgar can "cure malaria cold and heat, relieve heat and diarrhea in the summer, drink alcohol into a habit, convulsion, dizziness, blood stasis in the abdomen, and kill labor insects and chancre insects". And realgar stone, although poisonous, has also been used by doctors to fight poison with poison, treat scabies and sores, cold phlegm, asthma and cough.
Second, remove filth and ward off evil spirits. The ancient folk custom, every Dragon Boat Festival, often realgar into wine, sprinkle indoors and outdoors, or smear children's foreheads, ears and noses, hands and feet, etc., to repel evil spirits and remove filth, to prevent mosquitoes, snakes and scorpions. This custom originated from the ancients' cognition that realgar can repel poisonous insects and avoid evil spirits. In "The Legend of the White Snake", Bai Suzhen took realgar wine after drinking realgar wine at the Dragon Boat Festival, which shows the folk's belief in the effectiveness of realgar in removing filth and warding off evil spirits.
Third, alchemy and pharmaceuticals. In ancient alchemy, realgar and lily are all important things. Taoist priests want to use its chemical properties to refine the elixir of immortality. Although his pursuit of longevity has not been completed, the exploration of drug properties and chemical reactions in the process of alchemy has accumulated experience for the development For example, in Ge Hong's "Baopuzi · Inner Chapter", there are many records about alchemy of realgar and other things.
Fourth, dyeing and craftsmanship. The bright color of realgar can be used as a pigment for painting, ceramic coloring and other processes. In traditional craftsmanship, it plays a unique role and adds the beauty of color.

To synthesize diborane, the method is as follows:
The direct combination of boron and hydrogen is feasible in theory, but the actual operation is quite difficult. The crystal structure of capped boron is stable, and it is not easy to combine it with hydrogen under ordinary conditions. Extreme conditions such as extreme temperature and high pressure are required, and the reaction is not easy to control, so this method is rarely used.
The common method is to react with lithium aluminum hydride and boron trifluoride in a suitable solvent. Lithium aluminum hydride (LiAlH) is a strong reducing agent; boron trifluoride (BF
) is an electron-deficient compound, and the two meet. The hydrogen negative ion (H <) in lithium aluminum hydride is transferred to the boron trifluoride atom, and the following reaction occurs: 3LiAlH+ 4BF
+ 3LiF + 3AlF
. This reaction is preferably carried out in organic solvents such as ether, which can dissolve the reactants and stabilize the reaction intermediates, so that the reaction occurs smoothly.
Another preparation is the reaction of sodium borohydride with sulfuric acid. Sodium borohydride (NaBH) is also a commonly used reducing agent. When it interacts with sulfuric acid (H2O SO), the reaction is roughly: 2NaBH+ H2O SO B ³ H+ Na ³ SO + 2H ². However, this reaction needs to pay attention to the concentration and drip rate of sulfuric acid. If it is not properly controlled, it is easy to cause the reaction to be too violent, and the product may be mixed with hydrogen and other impurities, which need to be separated and purified later.
After preparing diborane, it needs to be properly stored and used because of its high activity, toxicity and flammability. Storage should be in a special pressure-resistant, sealed and inert-lined container at low temperature, cool and well-ventilated to prevent it from decomposing or reacting dangerously with air.

When using an aldehyde lamp, be sure to pay attention to the following things:
First, check the lamp body carefully before use. See if it is damaged and whether the wick is in good condition. If the lamp body is damaged, it may cause aldehyde leakage, which is easy to cause disaster in case of fire; if the wick is damaged, the flame will be unstable and will also affect the use. Therefore, careful inspection can ensure that there is no danger when using it.
For the second time, add aldehyde, and be cautious. It is advisable to put out the flame first, and wait for the lamp body to be slightly cold. And the amount of injection should be moderate, not too full, generally two-thirds of the volume of the lamp body is appropriate. If it is too full, the aldehyde will easily overflow, and once it ignites, the disaster will come.
Furthermore, when the lamp is burning, the firewood or firearm in hand should be approached smoothly from the lower end of the wick, and must not be approached rapidly to prevent the fire from suddenly rising and injuring people. After the fire, when adjusting the wick carefully, so that the fire flame is moderate and stable.
Those who use it, do not place flammable objects next to the lamp. Although the aldehyde lamp is small, the temperature of the fire flame is quite high, and the flammable objects are placed nearby. If you are not careful, it will cause fire to burn and cause a disaster.
Finally, after the use is completed, when the lampshade is covered with fire, when the fire flame is completely extinguished, the lampshade can be removed. Do not blow it out with your mouth to prevent the fire from pouring into the lamp body with the flow, causing danger.
In short, when using an aldehyde lamp, you need to be careful in every step, and you must not be negligent, so as to ensure safety.

In today's city, the shape of the second jade porcelain boat is quite impressive. The art of the porcelain boat has been around for a long time. Since the ancient pottery, it has been in porcelain for thousands of years, and the skills have been refined and there are many categories. This jade porcelain boat has exquisite craftsmanship and unique shape, or is made by the careful ingenuity of craftsmen.
Looking at the scene of various cities, such porcelain boats are quite popular among collectors and scholars. The reason for this is that, on the one hand, the porcelain is warm and delicate, the color is elegant, and it has a very high aesthetic value; on the other hand, its shape is or imitates the shape of a natural boat, or contains auspicious meaning, which attracts reverie. Therefore, in the antique market, it is often the focus of attention.
However, its market situation is not blindly prosperous. In today's world, fakes are mixed, and the art of imitation is increasingly refined, which often makes it difficult for collectors to distinguish the authenticity. If you buy a fake, you will not only lose your wealth, but also damage the interest of collectors. It is because collectors are in the market, they need to have discerning eyes and be screened in detail.
And the price of the market also fluctuates. It is controlled by many factors, such as the distance of the age of the porcelain boat, the quality of the product, and the number of surviving people, which can affect its value. Rare treasures are expensive and difficult to find; ordinary imitations are cheap and fill the market. Therefore, between sales, you must not be careless.
The atmosphere of the market is also related to the market of the porcelain boat. At this time, the ancient trend is gradually flourishing, and the elegant things are highly respected, and the jade porcelain boat and the like are also booming. However, the trend is changing rapidly. If you don't pay attention to the current situation and enter the market rashly, you may also lose.
In short, the market prospect of the second jade porcelain boat, although it has potential, there are also risks. Those who enter the market need to be familiar with the market, distinguish the authenticity, and weigh the pros and cons in order to gain something in the city and get what they want.