The United States on Thursday imposed a new round of financial penalties on people and entities involved in Russia’s financial sector, with the targets including one of that country’s richest men, Vladimir Potanin, his family and a commercial bank he acquired this year. The Treasury Department’s Office of Foreign Assets Control also imposed sanctions on more than 40 people linked to the Russian financial sector and 17 subsidiaries of VTB Bank Public Joint Stock Company — also known as VTB Bank — Russia’s second largest bank. VTB Bank was designated for sanctions in February. The State Department issued separate diplomatic designations on the people and companies.