Photochromic Indeno-Fused Naphthopyran Compounds for Temperature Stability
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Solution Overview
Problem
Photochromic compounds used in articles like eyewear lenses exhibit significant temperature dependence, leading to inconsistent coloration based on ambient temperature, with existing compounds either not darkening enough at high temperatures or becoming too dark at low temperatures.
Innovation Solution
Development of thermally reversible photochromic indeno-fused naphthopyran compounds with specific core skeletal structures, represented by Formula (I), that reduce temperature dependence by optimizing the chemical structure to maintain consistent optical density across temperature variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If thermally reversible photochromic compounds are used, then the compound transforms from unactivated to activated state in response to actinic radiation and reverts back in response to thermal energy, but the compound exhibits significant temperature dependence causing inconsistent coloration at different ambient temperatures
Solution Approach 1:
The patent modifies the chemical structure parameters of the photochromic compound by introducing specific substituents at defined positions on the naphthopyran core structure. These structural parameter changes alter the thermal and optical properties to reduce temperature dependence while maintaining photochromic functionality.
Solution Approach 2:
The invention creates a composite molecular structure combining the naphthopyran core with specific substituent groups (such as aryl, heteroaryl, or alkyl groups) to achieve synergistic effects that simultaneously provide photochromic activity and reduced temperature sensitivity.
2Reliability
If existing photochromic compounds are used in photochromic articles, then the articles provide photochromic functionality, but the coloration is affected by ambient temperature causing the article not to darken sufficiently at high temperatures or become too dark at low temperatures
Solution Approach 1:
The patent systematically varies substituent parameters (type, position, and nature of R1, R2, R3 groups) to optimize the balance between photochromic activity and temperature stability, ensuring reliable and consistent performance across different ambient conditions.
3Stability of the object's composition
If the chemical structure of photochromic compounds is optimized to reduce temperature dependence, then temperature stability is improved, but the structural complexity increases
Solution Approach 1:
The patent introduces functional substituents at specific local positions (R1 at position 2, R2 at position 6, R3 at position 7) on the naphthopyran core, allowing temperature stability to be achieved through localized structural modifications rather than global structural changes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The new photochromic compounds demonstrate improved temperature stability, ensuring consistent coloration and reduced temperature dependence, enhancing the performance of photochromic articles by maintaining desired optical properties across varying temperatures.
Implementation Method 1
Photochromic compounds undergo a transformation from one state (or form) to another state in response to certain wavelengths of electromagnetic radiation (i.e., 'actinic radiation')
Implementation Method 2
The activation reaction (from unactivated to activated) is primarily photochemical
Implementation Method 3
the deactivation reaction (from activated to deactivated) is primarily thermal
Data Source
AI summary
A photochromic compound including a core skeletal structure represented by the following Formula (I),wherein D is oxygen or sulfur; E is oxygen, sulfur, or NR2′; a is 0 or 1; R1 is hydrogen, or substituted or unsubstituted alkyl; R2 and R2′ are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or substituted or unsubstituted heterocycloalkyl; and the photochromic compound is a thermally reversible photochromic compound.