Organic raw material

In the vast field of organic chemistry, aluminium diisobutyl hydride holds its unique position and characteristics, and it is also well-known as Dibal.

In terms of appearance, aluminium diisobutyl hydride appears as a colorless liquid. Its relative molecular mass was precisely determined to be 122.22. This value is of great significance for studying its chemical properties and the stoichiometric relationships when participating in various chemical reactions.

In terms of density, at an environment of 25℃, its relative density is 0.789. This physical property makes it exhibit specific behavioral manifestations when mixed with other substances or subjected to separation operations. Its melting point reaches -47℃, which means that it will change from a solid state to a liquid state in a relatively low temperature environment. Such a low melting point characteristic also reflects some characteristics of its intermolecular forces. Its boiling point is 140℃ under a pressure of 0.533×10³Pa, and its viscosity is 18.0mPa·s at 25℃. These physical parameters jointly outline the variation law of its physical state under different temperatures, pressures and other conditions.

It is worth mentioning that aluminum diisobutyl hydride undergoes an extremely vigorous reaction with water, and the products of the reaction are hydrogen and isobutane. This reaction characteristic determines that it must be strictly avoided from coming into contact with water during storage and use; otherwise, dangerous situations may occur. In addition, tetrahydrofuran is not suitable as a solvent for diacetylenols. The reason is that when the two meet, a reaction occurs, and a coordination compound is formed. This is a key point that requires special attention in related chemical experiments and chemical production scenarios.

Like the vast majority of organoaluminium compounds, the actual structure of aluminium diisobutyl hydride is far more complex than what is merely shown through its empirical formula. Through a variety of advanced technical means (it should be noted here that these techniques do not include X-ray crystallography), researchers found that the compound exists in the form of dimers and trimers. Among these aggregates, the aluminum centers with tetrahedral structures share bridging hydride ligands, thus constituting their unique microstructure morphology. Due to the relatively small volume and strong alkalinity of hydrides, they are more favored in the structural formation process compared to alkyl bridging, and thus are more likely to form this aggregated state structure dominated by hydride bridging.

There are specific feasible methods for the preparation of aluminium diisobutyl hydride. It can be obtained by heating triisobutyl aluminum, which itself is a dimeric structure substance. During the heating process, a β -hydride elimination reaction is induced, and its chemical reaction equation is: (i-Bu ₃Al)₂ → (i-Bu ₂AlH)₂ + 2(CH₃)₂C=CH₂.

In the field of commercial circulation, although aluminum diisobutyl hydride itself can be purchased as a colorless liquid, in actual situations, it is more common to buy and distribute it in the form of solutions of organic solvents (such as toluene or hexane), which is often more convenient for storage, transportation and subsequent usage operations, etc.

In the vast field of organic chemistry, diisobutylaluminum hydride (DIBAL) has demonstrated unique and distinct reactive characteristics. The reaction process between DIBAL and electron-deficient compounds is relatively slow, while when it meets electron-rich compounds, the reaction occurs rapidly. This significant reaction difference indicates that DIBAL plays the role of an electrophilic reducing agent in the chemical reaction. In contrast, LiAlH4 (lithium aluminum hydride) can be regarded as a nucleophilic reducing agent, and there are obvious differences between the two in terms of reaction mechanism and properties.

In the complex and challenging field of organic synthesis, diisobutyl aluminum hydride plays an indispensable role and is widely involved in various reduction reactions. For example, in the transformation process involving carboxylic acids and their derivatives, DIBAL can play a precise role and drive the reaction in the expected direction. Similarly, in the conversion reaction of nitrile to aldehyde, it is also one of the key participants. It is worth mentioning that DIBAL has demonstrated outstanding ability in reducing α - β unsaturated esters to the corresponding allyl alcohols, and is capable of efficiently and selectively completing this conversion process.

However, when we focus our attention on the comparison between DIBAL and other reagents, some interesting phenomena will be found. For instance, LiAlH4 exhibits different behaviors in chemical reactions. It can smoothly reduce esters and acyl chlorides to primary alcohols, and when dealing with nitrile compounds, they can be reduced to primary amines by using the Fieser post-treatment procedure. By the same means, DIBAL can also reduce lactones to hemiacetals when facing them. To some extent, this hemiacetal is equivalent to an aldehyde, demonstrating DIBAL's unique transformation ability in a specific reaction.

In actual chemical practice, although DIBAL performs relatively reliably in the reaction of reducing nitriles to aldehydes and can generate the target products as expected, there are some thorny problems in the process of reducing esters to aldehydes. This reaction process is notorious, mainly because a large amount of alcohol is often produced as a by-product during this process. However, with the continuous development and innovation of chemical technology, scientists have discovered that by using the advanced technical means of continuous flow chemistry, the reaction conditions can be controlled more precisely and meticulously. Under such strict condition control, those unnecessary by-products can be effectively avoided, thereby improving the selectivity and efficiency of the reaction.

In addition, in the important chemical field of olefin polymerization, aluminium diisobutyl hydride has also been preliminarily studied and explored as a co-catalyst. This research attempts to lay a foundation for a further in-depth understanding of its mechanism of action and potential application value in olefin polymerization reactions, and is expected to play a greater role in future chemical research and industrial production.