The phrase "a string of unsuccessful" is correct and usable in written English.
It can be used to describe a series of failures or lack of success in a particular context.
Example: "The project was marked by a string of unsuccessful attempts to secure funding."
Alternatives: "a series of failures" or "a chain of unsuccessful efforts".
During the 80s and early 90s, they released a string of unsuccessful albums, though they remained a popular live attraction.
For Julie, it was a string of unsuccessful relationships, for Susan, the discovery of her beloved Barry's long-term porn addiction.
After a string of unsuccessful interviews in smart clothes, he finally found himself a job by being himself – bright green chinos and all.
The CPS is under pressure after a string of unsuccessful cases involving sexual assault and rape allegations against public figures, including Evans, Bill Roache and Michael Le Vell.
Ms. Friedland, who has spent much of the last four years living in Europe, had been through a string of unsuccessful relationships.
The newsroom, beleaguered by layoffs, a bankruptcy and a string of unsuccessful owners, gave Mr. Marimow a standing ovation on his way out the door at 7 p.m. last Monday.
There is Ethel Chen, 62, a retired librarian and a longtime Democratic Party loyalist with a string of previous unsuccessful campaigns under her belt.
The United States under-20 national team is set to open its World Cup qualifying tournament on Monday against Haiti in Puebla, Mexico, and the pressure is mounting on the team to reverse a recent string of unsuccessful results for American men at the youth level.
Mestres Out as President of Disney Unit : Entertainment: His resignation from Hollywood Pictures was expected after string of unsuccessful films.
But Gulati's legacy already has been tarnished by the first unsuccessful qualifying campaign since 1986, ending a string of seven consecutive trips to the World Cup.
In preparation for his return, since a lucrative but unsuccessful appearance on TV's Celebrity Big Brother, a string of trainers have been utilising Dettori's services on the gallops.
