1：Experimental Design and Method Selection:

The study involves synthesizing supramolecular donor-acceptor complexes with a methylene bridge, using femtosecond transient absorption and mid-IR spectroscopy to probe electron transfer dynamics, and electrochemistry to measure reduction potentials. Theoretical models include Gibbs free energy calculations for electron transfer reactions.

2：Sample Selection and Data Sources:

Samples are complexes 1 (Re(4-NDI-CH2-bpy)(CO)3Cl) and 2 (Mn(4-NDI-CH2-bpy)(CO)3Br) synthesized as described, with solvents like DMF and MeCN used for spectroscopy and electrochemistry.

3：List of Experimental Equipment and Materials:

Equipment includes Shimadzu UV-1800 spectrophotometer, Shimadzu IRAffinity FTIR spectrophotometer, CH Instruments Model 660A electrochemical workstation, femtosecond laser systems (Ti:sapphire amplifier, OPA amplifiers), Helios and Helios-IR spectrometers, and materials include TDAE reductant, TBAPF6 electrolyte, and various chemicals from Sigma-Aldrich and Oakwood Chemicals.

4：Experimental Procedures and Operational Workflow:

Synthesis of complexes, electrochemical measurements with cyclic voltammetry, steady-state UV-vis and FTIR spectroscopy, femtosecond transient absorption and mid-IR spectroscopy with excitation at 605 nm, data analysis using global fitting in MATLAB.

5：Data Analysis Methods:

Kinetic analysis using global fit to exponential models, deconvolution of spectra, calculation of quantum yields and rate constants, and comparison with electrochemical data.