In vivo fluorescence imaging in the shortwave infrared (SWIR, 1,000–1,700 nm) and extended SWIR (ESWIR, 1,700–2,700 nm) regions has tremendous potential for diagnostic imaging. Although image contrast has been shown to improve as longer wavelengths are accessed, the design and synthesis of organic fluorophores that emit in these regions is challenging. Here we synthesize a series of silicon-RosIndolizine (SiRos) fluorophores that exhibit peak emission wavelengths from 1,300–1,700 nm and emission onsets of 1,800–2,200 nm. We characterize the fluorophores photophysically (both steady-state and time-resolved), electrochemically and computationally using time-dependent density functional theory. Using two of the fluorophores (SiRos1300 and SiRos1550), we formulate nanoemulsions and use them for general systemic circulatory SWIR fluorescence imaging of the cardiovascular system in mice. These studies resulted in high-resolution SWIR images with well-defined vasculature visible throughout the entire circulatory system. This SiRos scaffold establishes design principles for generating long-wavelength emitting SWIR and ESWIR fluorophores.

短波红外（SWIR，1,000–1,700 nm）和扩展 SWIR（ESWIR，1,700–2,700 nm）区域的体内荧光成像在诊断成像方面具有巨大的潜力。虽然图像对比度已被证明随着波长的增加而提高，但在这些区域发射的有机荧光团的设计和合成具有挑战性。在这里，我们合成了一系列硅-RosIndolizine (SiRos) 荧光团，其峰值发射波长为 1,300–1,700 nm，发射起始波长为 1,800–2,200 nm。我们使用时间相关的密度泛函理论从光物理（稳态和时间分辨）、电化学和计算上表征荧光团。我们使用两种荧光团（SiRos1300 和 SiRos1550）配制纳米乳液，并将其用于小鼠心血管系统的一般全身循环短波红外荧光成像。这些研究产生了高分辨率短波红外图像，整个循环系统中清晰可见的脉管系统。该 SiRos 支架确立了产生长波长发射 SWIR 和 ESWIR 荧光团的设计原则。