Sheikh Mohammed bin Abdulrahman al-Thani, center, is the new chairman of the Qatar Investment Authority. : Get the DealBook newsletter to make sense of major business and policy headlines — and the power-brokers who shape them.__________ The reported purchase of an upmarket London hotel by Qatar suggests that the state’s $300 billion national wealth fund is shifting its investment focus. Qatar is reportedly buying the high-profile London hotel Grosvenor House, according to Reuters, which cited unidentified sources.