Abstract: An immersion liquid, especially for microscopy, contains one or more acetals of tricyclodecane alcohols as its main constituent, wherein a tricyclodecane alcohol is a compound of which the structure has the base skeleton of tricyclo[5.2.1.02,6]decane and at least one OH group, and wherein all OH groups of the tricyclodecane alcohol have been acetalized in the acetal. Also described are 3(4),8(9)-bis(tetrahydropyran-2-yloxymethyl)tricyclo[5.2.1.02,6]decane or 8-tetrahydropyran-2-yloxymethyltricyclo[5.2.1.02,6]decane and the preparation thereof, and the use of acetals of tricyclodecane alcohols as the main constituent of an immersion liquid. A process for preparing an acetal of a tricyclodecane alcohol involves reacting a tricyclodecane alcohol with an acetalizing agent in the presence of an acid.

Abstract: An immersion oil for microscopy contains a) a first diester A1 based on a tricyclodecane radical K having one functional group and a first hydrocarbon derivative C1 having two functional groups, and b) a second diester A2 based on the tricyclodecane radical K having one functional group and a second hydrocarbon derivative C2 having two functional groups, where C1 and C2 are different. Methods can be used for the production of the immersion oil and for the use thereof in microscopy.