Mass spectrometers are used by almost all chemists and many researchers from neighboring disciplines such as physics, medicine, or biology as a powerful a- lytical tool. Its advantages are high sensitivity, speed, and almost no sample c- sumption. During the last two decades, mass spectrometry experienced a boom of new developments pushing its limits further and further at an increasing speed just similar to the progress in NMR spectroscopy in the 1970s. However, a mass spectrometer does not only serve as a machine for solving complicated analytical problems, it evolved meanwhile to a complete laboratory for the investigation of molecules, clusters, and other species under the envir- ment-free conditions of the highly diluted gas phase. These special conditions existing only in high vacuum change the properties of the particles under study significantly with respect to their energetics and reaction pathways. For ex- ple, temperature is a macroscopic property of a large ensemble of particles in thermal equilibrium and is thus not defined for a single ion. This fact has severe implications for the measurement of kinetic and thermodynamic data of g- phase species. On the other hand, the examination of gas-phase properties has the advantage that systems reduced to minimum complexity can be studied more easily without the complicated influences of solvents or counterions. In parti- lar, the combination of isotopic labeling and mass spectrometry allows for a detailed analysis of reaction mechanisms or conformational analysis through H/D exchange experiments not only on biomole

With the present issue of Topics in Current Chemistry, the fourth and final volume concluding the mini-series on dendrimer chemistry has appeared. With a focus on the interdisciplinary bridges to neighboring fields, the contributions to this volume focus on coordination, catalysis and self-assembly, nicely balanced by a synthesis-based article on dendritic oligoethers.

The?rsttwovolumesinthis"TemplatesinChemistry"serieshavefocused on templates that controlsolution-phase reactions. Among the templates d- cussed in these two volumes were convex and concave templates that mediate the formation of (macro)cyclic molecules and mechanically bound molecules withtheir intriguingintertwined topology.Also,three-dimensional templates that are used to imprint polymers and that organize compounds in the solid state for predestined reactions have been included in the earlier volumes. In the present volume, we extend thetemplate topologytosurfaces that act asmatricesforthecontrolledgrowthoftwo-dimensionalarrays.Naturally,the typical methods for the characterization of surfaces such as scanning probe microscopyare prominently represented in this volume. Differentlateralinteractionssuchascoordinativebondsorhydrogenbo- ing play a major role in assembling the 2D networks on surfaces in addition to the interaction of the samples with the underlying substrates. Many p- nomena that are also encountered in solution can be directly visualized on surfaces: Reversible self-assembly processes lead to the formation of large structures through multiple recognition of small building blocks and cul- nate in the engineering of crystals in two dimensions. Self-sorting processes drive the formation of highly ordered arrays through the geometric ?t of the available components. Either the surface itself is the template, for example, when clusters grow on metal oxide ?lms, or colloidal templates control the formationof macroporousnetworksonthe substrate. This volume highlightsa selection of actual complementary aspects of s- facetemplates.Webelievethatthescopeandthevarietyoftopicscoveredinthis volume will attract readers fromdifferent communities such as supramole- larchemistry,materialsciences,surfacechemistry,surfacephysicsandsurface technologyandwehopetheywillenjoythisnewvolumeonTemplatesinCh- istry.