1. Introduction
2. Observations and Ancillary Data
2.1. PdBI Observations and Data Reduction
2.2. Integrated Intensity Maps
2.3. Ancillary Data
2.4. Multi-wavelength Gallery of the Central Region of NGC 6946
3. Results – Molecules in Different Environmental Regions in the Centre of NGC 6946
3.1. The Substructures in the Inner Kiloparsec of NGC 6946
3.2. Molecular Line Profiles Towards the Nuclear Region and What They are Indicating
4. The Environmental Variability of the Star Formation Rate in NGC 6946
5. Results - Line Ratios and Relationships Among Molecular Species
5.1. Ratios of Integrated Intensities
5.2. The Relationship Between Molecular Lines and SFR Surface Density
6. Implications for Spectroscopic Studies of Other Galaxies – From Bulk Molecular Gas to Dense Gas
6.1. R21 Variations in the Nuclear Region and Inner Bar Ends
6.2. HNC / HCN: Sensitive to Kinetic Temperatures in Extragalactic Environments?
6.3. Examining Ratios Among HCN, HCO+ and HNC as a Diagnostic of AGN State
6.4. Density Variations at the Inner Bar Ends and Nuclear Region
7. Conclusion