How do I remove the blank line between citations using the achemso package?

Question

I'm using the achemso package (but not the achemso class) to format my citations, but would like to remove the blank line between citations. Here is a MWE demonstrating my current output:

documentclass[]{article}
\usepackage[etalmode=truncate, maxauthors=2]{achemso}                            

\begin{filecontents}{\jobname.bib}
@Article{Leznoff,
author ="Hayes, Cassandra E. and Leznoff, Daniel B.",
title  ="Paramagnetic metal complexes of diamido donor ligands",
journal  ="Dalton Trans.",
year  ="2012",
volume  ="41",
pages  ="5743",
}
@article{poly,
author = {Schrock, Richard R. and Baumann, Robert and Reid, Steven M. and Goodman, Jonathan T. and Stumpf, Rüdiger and Davis, William M.},
title = {Synthesis of Titanium, Zirconium, and Hafnium Complexes that Contain Diamido Donor Ligands of the Type [(t-BuN-o-C6H4)2O]2- and an Evaluation of Activated Versions for the Polymerization of 1-Hexene},
journal = {Organometallics},
volume = {18},
pages = {3649},
year = {1999},
}

\end{filecontents}

\begin{document}
Here is a really awesome grant proposal.\cite{Leznoff}. 
Sadly it wastes space with blank lines between each citation.\cite{poly}

\bibliography{\jobname}

\end{document}

I'd like to do something like

documentclass[]{article}
\usepackage[etalmode=truncate, maxauthors=2]{achemso}                            

\begin{filecontents}{\jobname.bib}
@Article{Leznoff,
author ="Hayes, Cassandra E. and Leznoff, Daniel B.",
title  ="Paramagnetic metal complexes of diamido donor ligands",
journal  ="Dalton Trans.",
year  ="2012",
volume  ="41",
pages  ="5743",
}
@article{poly,
author = {Schrock, Richard R. and Baumann, Robert and Reid, Steven M. and Goodman, Jonathan T. and Stumpf, Rüdiger and Davis, William M.},
title = {Synthesis of Titanium, Zirconium, and Hafnium Complexes that Contain Diamido Donor Ligands of the Type [(t-BuN-o-C6H4)2O]2- and an Evaluation of Activated Versions for the Polymerization of 1-Hexene},
journal = {Organometallics},
volume = {18},
pages = {3649},
year = {1999},
}

\end{filecontents}

\begin{document}
Here is a really awesome grant proposal.\cite{Leznoff}. 
Sadly it wastes space with blank lines between each citation.\cite{poly}

{\singlespacing
\bibliography{\jobname}
}
\end{document}

But that doesn't work.

Answer 1

The separation you see is the \itemsep, that the achemso package sets in the bibliography equal to \bibsep. So the answer is to declare

\setlength{\bibsep}{0pt}

in your preamble. Use a different value if you want some spacing. The default is 8.0pt plus 4.0pt minus 2.0pt (it's a rubber length).