Tris[4-(1,1-dimethylethyl)-2-(1H-pyrazol-1-yl)pyridine]cobalt salt with 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide (1:3)
[CAS# 1447938-61-5]

Identification

• Classification: Organic raw materials >> Organometallic compound
• Name: Tris[4-(1,1-dimethylethyl)-2-(1H-pyrazol-1-yl)pyridine]cobalt salt with 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide (1:3)
• Molecular Formula: C₃₆H₄₅CoN₉^.3(C₂F₆NO₄S₂)
• Molecular Weight: 1503.16
• CAS Registry Number: 1447938-61-5
• EC Number: 827-114-0
• SMILES: CC(C)(C)c1ccnc(-n2cccn2)c1.CC(C)(C)c1ccnc(-n2cccn2)c1.CC(C)(C)c1ccnc(-n2cccn2)c1.O=S(=O)([N-]S(=O)(=O)C(F)(F)F)C(F)(F)F.O=S(=O)([N-]S(=O)(=O)C(F)(F)F)C(F)(F)F.O=S(=O)([N-]S(=O)(=O)C(F)(F)F)C(F)(F)F.[Co+3]

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovory and Applicatios

Tris[4-(1,1-dimethylethyl)-2-(1H-pyrazol-1-yl)pyridine]cobalt salt with 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide (1:3) is a synthetic coordination complex developed for use in advanced functional materials, particularly in electrochemical and optoelectronic systems. The compound consists of a cobalt center coordinated by three bidentate ligands, each derived from 4-(1,1-dimethylethyl)-2-(1H-pyrazol-1-yl)pyridine, forming a stable tris-chelated cobalt complex. This cationic complex is paired with three equivalents of 1,1,1-trifluoro-N-\[(trifluoromethyl)sulfonyl]methanesulfonamide, also known as the bis(trifluoromethanesulfonyl)imide (TFSI) anion, which serves as a non-coordinating counterion.

The discovery of this class of cobalt complexes is linked to the exploration of transition metal coordination compounds as efficient redox mediators and charge-transport materials. The steric bulk provided by the tert-butyl substituents on the pyridine ring increases the solubility of the complex in organic solvents and enhances its stability against ligand dissociation. The pyrazolylpyridine framework, being a strong chelating motif, secures the cobalt center in a well-defined coordination environment, thereby allowing fine-tuning of its electrochemical properties.

One of the most prominent applications of this cobalt salt is in the field of dye-sensitized solar cells (DSSCs). It has been employed as a redox mediator in place of the traditional iodide/triiodide system. The cobalt-based redox shuttle allows for improved photovoltage due to its higher redox potential, while the bulky ligands help suppress charge recombination at the photoanode interface. The use of the TFSI counterion further contributes to favorable ionic conductivity and electrochemical stability, both of which are crucial for long-term device performance.

In addition to its role in DSSCs, this cobalt complex has been studied in other electrochemical devices such as redox flow batteries and electrochromic systems. Its redox-active cobalt center can undergo reversible electron transfer processes, while the ligand design ensures chemical robustness during repeated redox cycling. The strong electron-withdrawing properties of the TFSI anion minimize ion pairing effects and facilitate fast charge transport in solution or within solid-state electrolytes.

The synthesis of the cobalt complex typically involves coordination of the tris(pyrazolylpyridine) ligands to a cobalt(II) or cobalt(III) precursor, followed by anion exchange to introduce the TFSI counterions. The resulting salt is usually isolated as a crystalline solid with good thermal stability. Structural characterization through X-ray diffraction has confirmed the octahedral geometry around the cobalt center, with three chelating ligands occupying all six coordination sites.

Beyond energy conversion and storage applications, the compound has attracted attention in fundamental coordination chemistry due to its tunable electronic properties. By altering the substituents on the pyrazolylpyridine ligands, researchers can modulate the redox potential of the cobalt center, providing a platform for the systematic study of structure–property relationships in transition metal complexes.

In conclusion, tris[4-(1,1-dimethylethyl)-2-(1H-pyrazol-1-yl)pyridine]cobalt salt with 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide (1:3) represents a carefully designed coordination complex at the intersection of inorganic chemistry and materials science. Its discovery stems from efforts to develop new cobalt-based redox mediators, and its applications span solar energy harvesting, electrochemical energy storage, and advanced optoelectronic systems. The combination of sterically protected ligands and highly stable TFSI counterions ensures both chemical resilience and high performance, making it a benchmark compound in the study of cobalt coordination complexes for functional applications.