chemBlink Search Help
How to search by product name
You may enter product name in whole or in part as keywords into the search box.
All the following terms are valid for searching for the compound
The more detailed the search terms are, the easier to find the target product,
while a concise and general search word may show a wide range of results for a
further selection. To avoid returning too many unrelated results, only the
boolean AND is used in multiple keyword searching strings. For instance, when
searching methyl alcohol, propyl alcohol or methyl bromide will never be
returned. For accurate searching the double quotation mark can be used.
The keywords are not case-sensitive.
How to search by CAS registry number
You must use valid formats to enter a CAS number or its segments for search.
Only numbers and the dash mark are acceptable. The longest complete CAS number
has the form of 123456-78-9. The first set of numbers may vary from 1 to 6
digits, while the third and the second sets can only hold 1 and 2 digits,
respectively. The following valid search terms provide various results:
How to search by molecular formula
The acceptable character set for composing search terms by molecular formula
includes letters (A-Z, a-z) for element symbols, numbers (0-9) for specifying
composition, the period (.) and parentheses as separator, and the comma(,) as
the European decimal point. Using any other characters will definitely lead to
The element symbols are capital-sensitive. Si and SI will be decoded as silicon
and the unit of sulphur and iodine, respectively. Blank spaces between element
symbols or numbers are allowed. There is no requirement for sequence of
symbols. In most cases a simple summarized form is recommended. For example,
the following two search terms are identical and will bring all products in the
database whose composition matches the formula or contains it as a fragment:
It should be noted that each symbols should be summarized. For example, the
search term C6H5OH for phenol is invalid. The correct search terms are C6H6O or
C6H5.OH (see the fragment format below).
For ligand compounds or macro-molecules using the format of fragments is more
convenient. You should use the period to separate segments, while each segment
can be composed as same as in the case of a simple molecule. In such a way you
can decompose a complex molecule into parts for easy understanding:
You can specify as many fragments as you like provided that separating them
with periods. You may use prefix or suffix to define a multi-ligand unit. It
should be noted that the prefix and suffix must be used along with parentheses.
Besides, there is only one pair of parentheses allowed within one fragment. The
following search terms are invalid:
The correct forms are C23H46N6O13.3(H2SO4) and (C9H10N2O4).(H2O) (or
C9H10N2O4.H2O). However, the nested single pairs of parentheses are needed for searching the following products, which include multiple complex anions:
It is very possible that there are non-integer numbers in a formula. You must
use the European decimal point (that is, the comma) along with parentheses
instead of a dot. For example:
For searching polymers non-numerical suffix m, n or k are frequently used:
The term of searching for polyethylene:(CH2)m
The term of searching for poly(ether sulfone):
How to search by supplier's name or URL
Simply enter the full or a part of the supplier's name or URL to be
searched in the search box. The search keywords are not case-sensitive.