# What kind of water would Oxygen-15 and tritium create?

I've recently become interested in chemistry, and have some questions about water.

I've heard of semi-heavy, heavy, tritiated, and oxygen-heavy water. However, what about various combinations of isotopes? Let's say: Oxygen 15 + Tritium? How about Oxygen 18 + Deuterium?

Would these all have distinct properties from one another? Have all the stable combinations been extensively studied and lab tested?

• Oxygen-15 has half-life of about 2 minutes... – Mithoron Jul 21 '17 at 20:58
• @Mithoron That's true, but water Oxygen-15 is used to measure tissue or tumor blood flow/perfusion. I'm more curious about the physical differences between the different combinations of isotopes rather than the practicality of making it. – Yonah Paley Jul 21 '17 at 21:45
• Yeah it's used in PET, but you can't get macroscopic amounts of its compounds. – Mithoron Jul 21 '17 at 22:15
• Because of the dynamic equilibrium of autoprotolysis of water ($\ce{H2O <<=> H+ + OH-}$ the isolation of water with mixed isotopes of H (like pure HDO, or HTO) is hampered. From a probabilistic approach, the natural abundance of $\ce{^2H}$ equals to 0.02% and the one of $\ce{^{17}O}$ to 0.04%. In other words, only 0.000016% chance to encounter a molecule of $\ce{D2^{17}O}$ outside a scientific lab, and expensive (medicalisotopes.com/product-category.php?id=2) For molecules consisting of short-living isotopes, you will need a rapid characterization, mass spectroscopy may be one. – Buttonwood Jul 21 '17 at 22:38
• They would vibrate differently (in terms of frequency) leading to slightly different boiling point and kinetic properties. That's kind of it. – jheindel Jul 31 '17 at 2:29