ДИРОДИЙ (II) ТЕТРАКИС (КАПРОЛАКТАМ)

Description

Dirchodium(II) tetrakis(caprolactam) is a binuclear coordination complex of rhodium(II) in which four caprolactam molecules play the bridging role instead of acetate ligands. English name Dirhodium(II) tetrakis(caprolactam), CAS 138984-26-6, chemical formula C24H44N4O4Rh2. The compound is known in the chemistry of catalysis as the Doyle catalyst - Rh2(cap)4, used in reactions involving diazo compounds.

Basic Attributes

• CAS No: 138984-26-6
• Chemical formula: C24H44N4O4Rh2
• Molecular Weight: 658.44
• Exact weight: 658.147
• PSA specification: 116.40
• XLogP3: 4.0216

Scope of application

Doyle's catalyst is used in fine organic synthesis for reactions involving the introduction of a carbene fragment generated by the decomposition of diazo compounds at C–H, N–H and O–H bonds, as well as for the cyclopropanation of alkenes. Compared to the acetate analogue, lactam ligands impart a different electron density to the complex at the metal center, which changes the selectivity of the reaction and makes the catalyst useful for transformations where the acetate complex provides insufficient regioselectivity. Used in academic and industrial laboratories of organic synthesis, including in the preparation of pharmaceutical intermediates.

Chemical nature of the complex

As in dirchodium tetraacetate, two rhodium atoms are linked by a direct metal-to-metal bond and surrounded by four bridging ligands—in this case, deprotonated or coordinated via carbonyl oxygen and nitrogen molecules of caprolactam (a cyclic amide). This structure belongs to a large family of dirchodium catalysts that differ in the nature of the bridging ligand while maintaining a common binuclear framework.

Safety Information

The manufacturer's source data does not contain information about the GHS classification, transport codes, RTECS number and WGK Germany indicator. As with other rhodium-based organometallic catalysts, it is recommended to follow standard protective measures when working: gloves, safety glasses, a fume hood, avoiding inhalation of fine powder. The absence of a published classification does not mean that the product is completely safe - work with any new organometallic reagent begins with minimal quantities, assessing stability and compatibility with the reaction medium.

Storage and transportation conditions

Store in an airtight container in a cool, dry place, away from direct light and moisture, as is typical for oxidation-sensitive organometallic catalysts. Transport in the manufacturer's original packaging, avoiding mechanical damage to the container and moisture, which can initiate decomposition of the complex.

Economics of application

Like other rhodium-based catalysts, the compound is used in catalytic quantities—usually fractions of a mole percent of the substrate—which makes its use economically feasible even at the high cost of the platinum group metal. After completion of the reaction, the residual rhodium is usually removed from the reaction mass and returned to circulation.