Table 1.

Selected structural parameters, spectroscopic data, and HOMO–LUMO and singlet–triplet energy gaps for the acyclic silylenes

	∠E–Si–E'/°	d(Si–E)/Å	29Si chemical shifts (δ)	λ max[nm]	HOMO–LUMO gap [eV]	Singlet–triplet gap (kJ/mol)
:Si{B(NDippCH)2}{N(SiMe3)‐Dipp} (14)	B–Si–N	Si–B: 2.066(1)	+439.7	–	2.04a	103.9a
	109.7(1)	Si–N: 1.731(1)
:Si(SArMe6)2 (17a)	S–Si–S	Si–S: 2.1607(5)	+285.5	382	4.26b	–
	90.519(19)	Si–S: 2.1560(5)
:Si(SAriPr4)2 (17b)	S–Si–S	Si–S: 2.137(1)	+270.4	405	–	–
	85.08(5)	Si–S: 2.137(1)
:Si(SAriPr6)2 (17c)	S–Si–S	Si–S: 2.089(9)c	+270.9	411	–	–
	84.8(1)
:Si{Si(SiMe3)3}{N(SiMe3)‐Dipp} (15)	N–Si–Si	Si–Si: 2.386(1)	+438.2	–	1.99a	103.7a
	116.91(5)	Si–N: 1.720(1)	+467.5
:Si(TBoN)2 (19)	N–Si–N	Si–N: 1.7495(10)	+204.6	385	2.55d	158.3d
	110.94(5)	Si–N: 1.7432(10)
:Si(OSitBu3)(IPrN) (21)	N–Si–O	Si–N: 1.661(2)	+58.9	328	4.33e	–
	103.56(8)	Si–O: 1.643(1)
:Si[(HCDippN)2BO]2 (24)	O–Si–O	Si–O: 1.6074(14)	+35.5	348	5.45f	–
	100.02(8)	Si–O: 1.6052(14)
:Si(MeIPrCH){Si(SiMe3)3} (27)	C–Si–Si	Si–C: 1.798(2)	+432.9	583	4.79g	–
	101.59(7)	Si–Si: 2.404(1)
:Si(IPrN){Si(SiMe3)3} (37a)	–	–	+300.0	612	2.96h	103.9h
:Si(SitBu3){Si(SiMe3)3} (40)	–	–	–	–	4.18i	10.5i
:Si[Ga(Br)L]2 (46)	–	–	–	–	2.7j	5.9j

^aCalculated at the PBE/TZ2P level of theory.

^bCalculated at the PBE1PBE/def2‐TZVP level of theory.

^cAveraged value.

^dCalculations at the BP86/TZP level of theory were performed on the molecule with its Dipp substituents replaced by 2,6‐dimethylphenyl groups.

^eCalculated at the B3LYP/6‐311+G(d) level of theory.

^fCalculated at the PBE1PBE/TZVP level of theory.

^gCalculated at the M06‐2X/def2‐TZVP level of theory. See the reference.42

^hCalculations at the B3LYP/6‐311+G(d,p) level of theory were performed on the molecule with its Dipp substituents replaced by phenyl groups.

ⁱCalculated at the M06‐2X/6‐31+G(d,p) level of theory.

^jCalculated at the B3LYP‐D3(BJ)/6‐311G(d,p), def2‐TZVP (Ga and Br) level of theory.