Package 'libmongoc-1.0', required by 'libmongocxx', not found

Question

I am trying to get the libmongocxx to run on Debian Jessie 64bit after compiling it according to the : quickstartguide

I added the path the find command returned as the location for the libmongoc-1.0.pc file the compiler is complaining missing:

$: sudo find / -name "libmongoc-1.0.pc"

/opt/mongo-c-driver/src/libmongoc-1.0.pc
/opt/mongo-c/lib/pkgconfig/libmongoc-1.0.pc

I try to set the dependency specific in the pkg path declaration:

 PKG_CONFIG_PATH=/opt/mongo-c/lib/pkgconfig c++ --std=c++11 main.cpp -  o hellomongo $(pkg-config --cflags --libs libmongocxx)

But I keep getting this error given xx different tries:

  Package libmongoc-1.0 was not found in the pkg-config search path.
  Perhaps you should add the directory containing `libmongoc-1.0.pc'
  to the PKG_CONFIG_PATH environment variable
  Package 'libmongoc-1.0', required by 'libmongocxx', not found
  c++: error: main.cpp: No such file or directory
  c++: fatal error: no input files
  compilation terminated.

I hope somebody can enligthen me.