Obsessed with Anna Ivanova Popova, Dmitri Mendeleev threatened suicide if she refused

Dmitri Ivanovich Mendeleev (8 February 1834 – 2 February 1907), was a Russian chemist and inventor. He is credited as being the creator of the first version of the periodic table of elements. Using the table, he predicted the properties of elements yet to be discovered. Mendeleev is thought to be the youngest of 14 siblings.

In 1862, he married Feozva Nikitichna Leshcheva. Mendeleev became Professor of Chemistry at the Saint Petersburg Technological Institute and Saint Petersburg State University in 1863. In 1865 he became Doctor of Science. He achieved tenure in 1867, and by 1871 had transformed Saint Petersburg into an internationally recognized center for chemistry research. In 1876, he became obsessed with Anna Ivanova Popova and began courting her; in 1881 he proposed to her and threatened suicide if she refused. His divorce from Leshcheva was finalized one month after he had married Popova in early 1882. Even after the divorce, Mendeleev was technically a bigamist; the Russian Orthodox Church required at least 7 years before lawful re-marriage. His divorce and the surrounding controversy contributed to his failure to be admitted to the Russian Academy of Sciences (despite his international fame by that time).

Bigamy is the act or condition of a person marrying another person while still being lawfully married to a second person. Bigamy is listed (and sometimes prosecuted) as a crime in most western countries. For example, in the United States, by law, a married person is not allowed to marry again as long as their first marriage continues.

Polygamy is any "form of marriage in which a person [has] more than one spouse."