A preprint is an academic journal article in draft form, prior to peer review. A postprint is a name given to a journal article once it has been peer reviewed. Both of these types of documents are known collectively as eprints.
There has been a movement since the early 1990s to make preprints available online, to aid the speed at which scientific knowledge can be disseminated. This movement began with ArXiv, a physics focused preprint server which has expanded to cover computer science, mathematics and other sciences.
The sharing of preprints online has expanded to other disciplines. This video mentions biological sciences, but there are also chemistry-focused sources of preprints, which you can discover on this guide.
Preprints allow you to access the latest research, without having to wait for a paper to be peer reviewed, accepted and published. This has benefits for those producing and reading research.
Journal peer review can be a slow process. Rapid dissemination of research ideas and data benefits researchers, their funders, and the public. Preprints provide a mechanism for authors to receive more rapid feedback on their research.
Eprints (electronically available preprints and postprints) are an important part of the Open Science movement.
Preprints can lead to greater reliability of research findings by fostering broad collaborations, improving the speed to sharing research findings, providing greater transparency to the communication cycle, and increasing the accessibility of findings
There are a wide range of online repositories for preprints and eprints. Some focus on a particular discipline, while others may host documents produced by a specific institution such as a university or research centre. We've listed some of the most relevant sources of preprints for chemistry here for you!
Many preprint services will perform basic checks for plagiarism and non-scientific content, and some may have communities of editors who quality check papers. If you find a preprint that is more than a few months old it would be worth checking for a final published version: you can do that by searching for the paper title or author on OneSearch or another database.
A Chemistry-focused landing page for PLOS ONE can be found at: https://journals.plos.org/plosone/browse/chemistry
Lancaster University Library can support researchers through the Open Access process. Visit http://www.lancaster.ac.uk/library/open-access/ for more information.