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The discovery of bright but stable pigments is extremely rare, making them enormously valuable. Now, chemist Mas Subramanian is cracking the atomic color code and getting closer to the most sought-after shade.
More Rajeevi Subramanianhusband and wife, both chemists by profession, visit art museums all over the world.
Rajeevi Subramanian was indeed an art lover and creator, producing exquisite sketches and watercolors. Mas Subramanian built a career in materials science at the chemical company DuPont, as reported in an article by .
But… something changed in 2008, when art and chemistry collided in Mas’s laboratory. While producing new materials for computers, the chemist came across a exotic blue pigment — an accidental discovery that would alter the course of his entire career and quietly reshape the way he viewed paintings.
Suddenly captivated by the hidden chemistry of colorscientists began to appreciate what has been a long-standing artistic frustration: Throughout history, bright, fade-resistant colors have been difficult to obtain, and the best ones have been found by chance rather than by design.
For Subramanian, this difficulty represented an irresistible scientific challenge. He became obsessed with color and determined to identify the atomic structures that give rise to it.
Pigments in almost every shade came out of his laboratory. However, today, a prize still eludes him: the most elusive color in the world, a perfect red.
Red has never been hard to find. What has always proved elusive is a red that is simultaneously bright and long-lasting.
Historically, the brightest inorganic reds relied on toxic metals like cadmium or the Mercury. However, these materials are increasingly out of use, and replacing them has turned out to be much more difficult than expected.
The problem seems simple. As New Scientist explains, a material appears red because it reflects red light while absorbing blue and green. However, in practice, the most striking pigments are those that reflect only the desired color, without spectral leakage. Get this depends on how the atoms are organized.
“Many companies have told me that, Whoever gets the red pigment can make me a billionaire”, disse Subramanian.
According to New Scientist, the global market for inorganic pigments is already worth more than 23 billion euros per year.
Red… always a problem
Subramanian quickly realized that red was going to be a problem that couldn’t be solved simply by choosing the right elements.
Chemists have long known that the same atom can produce very different colors depending on how it is bonded. Chromium, for example, gives green in emeralds but red in rubies, purely due to differences in the way the atoms are arranged in each crystal.
As New Scientist explains, ultimately color is governed by what light does to electrons. When light hits a pigment, its energy can cause electrons to “jump” to a higher energy level.
Which jumps are allowed — and which wavelengths of light are absorbed and reflected — depends on the atomic-scale structure of the material. Electrons can jump between atoms, for example, or between energy levels within the same atom.
In fact, It’s hard to know what leaps will occurbecause they depend on subtle factors: the distances between atoms, how much they are already filled with electrons and the rules of quantum physics.
In many crystal structures, these rules categorically prohibit the very transitions that would produce vivid color.
How Subramanian surpassed him
Rather than face this complexity head-on, Subramanian began looking for ways around it—using particularities of atomic geometry that allow quantum rules are relaxed.
In 2024, his search led him to compounds containing non-rare chromium Cr2+ statewhich is more common on the Moon than on Earth, where it is typically very unstable.
The chemist reduced the oxygen concentration in his furnace to lunar levels and managed to induce Cr2+ to form unusual crystalline structures, where chromium atoms are found in flat squares.
The result wasn’t the elusive red I was looking for — but it was close. Some compounds emerged as “reddish-magenta”suggesting he was on the right track.
Rather than relying solely on subtle jumps of electrons within atoms, Subramanian is also experimenting with semiconductor materials that absorb light when electrons jump completely out of their orbits—just as happens in canary-colored (but toxic) cadmium sulfide.
Still, progress remains uncertain. Subramanian admits that he continues, “in a way, tossing the dice.”
