Synthesis · Electrically conductive [Fe4S4]-based organometallic polymers

4 structured synthesis routes

Completeness describes how fully the route could be reconstructed from the main article and supporting information.

Partial recipeSource: Both

Route 1: Other

S7 · Controlled synthesis to vary the alkyl chains of NHC linkers · Fig. S6

Metal precursors(PPh4)2(Fe4S4Cl4), amount presumed as in procedure for 1

Linker precursorsR-BBI-X with R = Et, nPr, nBu; SI states X = I, while main text names Et-BBI-Br, nPr-BBI-Br and nBu-BBI-Br

SolventsDMF; DCM wash presumed as in procedure for 1

AdditivesNaOtBu presumed as in procedure for 1

AtmosphereN2

Temperature100

Time24

Oxidant / reductantNaOtBu base presumed for in situ NHC generation.

Work-upSame manner as procedure for 1; Fig. S6 notes 4-nBu PXRD collected without washing with DMF due to limited sample amount.

ActivationPresumed same as procedure for 1: vacuum drying at 100 C for 3 h.

Scalability contextLonger alkyl chains decreased yields, with almost no solid obtained for nBu-BBI-Br in main text.

Show 3 structured reagent records

Role	Reagent	Amount / concentration	Source
Linker	R-BBI-X (R = Et, nPr, nBu; X = I in SI)	not separately reported; same manner as procedure of 1	S7 · Controlled synthesis to vary the alkyl chains of NHC linkers · Fig. S6
Metal Source	(PPh4)2(Fe4S4Cl4)	not separately reported; same manner as procedure of 1	S7 · Controlled synthesis to vary the alkyl chains of NHC linkers · Fig. S6
Base	NaOtBu	not separately reported; same manner as procedure of 1	S7 · Controlled synthesis to vary the alkyl chains of NHC linkers · Fig. S6

Complete recipeSource: SI

Route 2: Other

S5 · Synthesis of R-BBI-X · Fig. S1

Linker precursorsTAB (1,2,4,5-benzenetetraamine tetrachloride), BBI, alkyl halides MeI/EtBr/PrBr/BuBr

SolventsFormic acid, deionized water, toluene, DMF

AdditivesK2CO3, NaH

AtmosphereN2 flow / under N2

Temperaturereflux; 0; 25; 80; 110

Time3 days formic-acid reflux; overnight 0 C; 2 h drying; 2 h NaH/toluene reflux; 2 h alkylation reflux; overnight 110 C

Oxidant / reductantNaH used as base for deprotonation

Work-upNeutralised with K2CO3 at 0 C; off-white BBI isolated by filtration, washed with ice-cooled DIW; R-BBI-X precipitation completed by toluene addition, isolated by filtration and washed with toluene.

ActivationBBI dried at 80 C under vacuum for 2 h; R-BBI-X dried at 80 C under vacuum for 2 h.

Show 8 structured reagent records

Role	Reagent	Amount / concentration	Source
Linker	TAB	2.272 mg, 8.00 mmol	S5 · Synthesis of R-BBI-X · Fig. S1
Acid	formic acid	80 mL	S5 · Synthesis of R-BBI-X · Fig. S1
Base	K2CO3	not reported	S5 · Synthesis of R-BBI-X · Fig. S1
Base	NaH	239.9 mg, 6 mmol	S5 · Synthesis of R-BBI-X · Fig. S1
Linker	BBI	474.5 mg, 3.00 mmol	S5 · Synthesis of R-BBI-X · Fig. S1
Linker	alkyl halide (MeI, EtBr, PrBr, BuBr)	18.0 mmol; MeI 1.12 mL; EtBr 1.34 mL; PrBr 1.64 mL; BuBr 1.82 mL	S5 · Synthesis of R-BBI-X · Fig. S1
Solvent	toluene	100 mL plus precipitation solvent	S5 · Synthesis of R-BBI-X · Fig. S1
Solvent	DMF	100 mL	S5 · Synthesis of R-BBI-X · Fig. S1

Complete recipeSource: Both

Route 3: Other

S7 · Synthesis of [Fe4S4Cl2(Me-NHC)] (1)

Metal precursors(PPh4)2(Fe4S4Cl4) (29.3 mg, 0.025 mmol)

Linker precursorsMe-BBI-I (58.8 mg, 0.125 mmol)

SolventsDMF (5 mL + 5 mL + 5 mL reaction solutions); DCM wash

AdditivesNaOtBu (24.0 mg, 0.25 mmol)

AtmosphereN2

Temperature25 then 100

Time25 min deprotonation at 25 C; 24 h at 100 C; 3 h drying

Oxidant / reductantNaOtBu base generates NHC linker in situ by deprotonation.

Work-upBlack precipitate isolated by centrifuge, washed with DMF (15 mL, 3 times) and DCM (10 mL, 3 times).

ActivationDried at 100 C under vacuum for 3 h.

Scalability contextSI states scale-up synthesis was performed in the same reaction scale and vial volume.

Show 5 structured reagent records

Role	Reagent	Amount / concentration	Source
Linker	Me-BBI-I	58.8 mg, 0.125 mmol · in 5 mL DMF	S7 · Synthesis of [Fe4S4Cl2(Me-NHC)] (1)
Base	NaOtBu	24.0 mg, 0.25 mmol · in 5 mL DMF	S7 · Synthesis of [Fe4S4Cl2(Me-NHC)] (1)
Metal Source	(PPh4)2(Fe4S4Cl4)	29.3 mg, 0.025 mmol · in 5 mL DMF	S7 · Synthesis of [Fe4S4Cl2(Me-NHC)] (1)
Solvent	DMF	15 mL total reaction solution; 15 mL x 3 washes	S7 · Synthesis of [Fe4S4Cl2(Me-NHC)] (1)
Solvent	DCM	10 mL x 3 washes	S7 · Synthesis of [Fe4S4Cl2(Me-NHC)] (1)

Complete recipeSource: SI

Route 4: Other

S5 · Synthesis of (PPh4)2(Fe4S4Cl4)

Metal precursorsFeCl2 anhydrous (1.4972 g, 11.8 mmol)

Linker precursorsNaSPh (2.2330 g, 17.7 mmol), sulfur powder (0.4745 g; text reports 0.48 mmol), Ph4PCl (2.227 g, 5.9 mmol)

SolventsMeCN (60 mL); Et2O (300 mL layered and for recrystallisation)

AtmosphereN2

Temperature25

Time2 h stirring plus 2 days Et2O layering at 25 C

Work-upFiltered to remove dark brown residue; Et2O layered; black crystals isolated by filtration, washed with Et2O, dissolved in minimum MeCN, recrystallised with Et2O, washed with Et2O.

ActivationDried under vacuum at 25 C

Scalability contextMain text calls this precursor synthetically scalable.

Show 6 structured reagent records

Role	Reagent	Amount / concentration	Source
Metal Source	FeCl2 anhydrous	1.4972 g, 11.8 mmol	S5 · Synthesis of (PPh4)2(Fe4S4Cl4)
Additive	Ph4PCl	2.227 g, 5.9 mmol	S5 · Synthesis of (PPh4)2(Fe4S4Cl4)
Linker	NaSPh	2.2330 g, 17.7 mmol	S5 · Synthesis of (PPh4)2(Fe4S4Cl4)
Other	S	0.4745 g, 0.48 mmol	S5 · Synthesis of (PPh4)2(Fe4S4Cl4)
Solvent	MeCN	60 mL	S5 · Synthesis of (PPh4)2(Fe4S4Cl4)
Solvent	Et2O	300 mL plus wash/recrystallisation solvent	S5 · Synthesis of (PPh4)2(Fe4S4Cl4)