A special iridium compound can make NMR signals much stronger for certain molecules like pyridine by using hydrogen gas, making it easier to detect these molecules in scientific tests.

Scientific Claim

The iridium complex [IrCl(COE)2]2 reacts with pyridine and hydrogen to form IrCl(H)2(COE)(py)2, which can hyperpolarize pyridine and related compounds via SABRE, enhancing NMR signal intensity by over 500-fold under optimal conditions.

Original Statement

“When this reaction is studied with parahydrogen, 1 efficiently achieves hyperpolarization of free py (and nicotinamide, nicotine, 5-aminopyrimidine, and 3,5-lutudine) via signal amplification by reversible exchange (SABRE) and hence reflects a simple and readily available precatayst for this process.”

From study:Iridium Cyclooctene Complex That Forms a Hyperpolarization Transfer Catalyst before Converting to a Binuclear C–H Bond Activation Product Responsible for Hydrogen Isotope Exchange

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The study describes an observed association between the iridium complex and hyperpolarization effects, but does not establish causation. The language 'efficiently achieves' is appropriate for an association claim in this context.

More Accurate Statement

“The iridium complex [IrCl(COE)2]2 reacts with pyridine and hydrogen to form IrCl(H)2(COE)(py)2, which is associated with hyperpolarization of pyridine and related compounds via SABRE, enhancing NMR signal intensity by over 500-fold under optimal conditions.”

Evidence from Studies

Supporting (1)

Iridium Cyclooctene Complex That Forms a Hyperpolarization Transfer Catalyst before Converting to a Binuclear C–H Bond Activation Product Responsible for Hydrogen Isotope Exchange

Case Report

In Vitro

2016 Nov 21

Contradicting (0)

No contradicting evidence found

Source Study

Iridium Cyclooctene Complex That Forms a Hyperpolarization Transfer Catalyst before Converting to a Binuclear C–H Bond Activation Product Responsible for Hydrogen Isotope Exchange

Score: 4

DOI: 10.1021/acs.inorgchem.6b02560

Similar Assertions

When this iridium compound is used with special hydrogen gas, it can make NMR signals for pyridine much stronger—over 200 times stronger in some cases.

82%

The iridium compound loses a pyridine molecule to form a simpler structure that helps transfer polarization during the SABRE process.

80%

When this iridium compound is exposed to special hydrogen gas, its hydrogen atoms show enhanced signals in NMR tests, which is a sign of polarization transfer.

77%

The iridium compound has parts that move around quickly at room temperature, with pyridine molecules leaving at about 8 times per second and hydrogen atoms swapping positions about 3.6 times per second.

76%

This iridium compound is easy to make, stable in air, and works better for hyperpolarization than the more complicated carbene-based catalysts usually used for this purpose.

75%